Your FREE Praxis Core Academic Skills for Educators Practice Test 2026 – 470+ Q&A

Correct answer: Honeybee colonies are declining for several reasons, and the loss puts the food supply at risk.

The passage opens with the alarm over declining colonies, ties their loss to the food supply, and stresses that pesticides, parasites, and habitat loss act together, so the main idea joins several causes with a serious threat to food. Singling out pesticides ignores the statement that no single factor explains the collapse, the pollination figure is only a supporting detail, and the passage describes scientists and farmers as equally alarmed, not in disagreement.

Correct answer: Several causes have to be tackled at the same time

The last sentence says no single factor explains the collapse and that solutions must address all of the causes at once, so the difficulty lies in tackling several problems together. The passage says researchers have identified the likely causes, it never discusses whether farmers rely on pesticides, and it presents pollination as what is at stake rather than as the obstacle to a solution.

Correct answer: A serious breakdown or failure

Here 'collapse' names what is happening to the bee colonies themselves: they are failing, the decline the passage has been describing. Nothing physical gives way, no prices fall, and no person faints, so those other senses of the word do not fit this context.

Correct answer: The library's modern glass design is the most beautiful structure downtown.

Calling the design 'the most beautiful structure downtown' is a personal judgment that cannot be checked, so it is the opinion. The opening date, the length of construction, the size of the collection, and the growth in membership can all be verified against records, which makes them facts.

Correct answer: Residents have responded well, as the growth in membership suggests.

Membership has grown by 40 percent since the opening, which points to a warm reception. The passage gives no figures on which parts of the library residents use or prefer, the praise of the glass design is the writer's opinion rather than the community's, and the growth in membership contradicts any claim that people were slow to use the building.

Correct answer: Clear up a common misconception with evidence

The passage names a popular belief, that knuckle cracking causes arthritis, and then cites studies showing no link, so its purpose is to correct that belief with evidence. It concludes that the habit poses no proven danger, mentions the gas bubbles only as one supporting fact, and notes that the habit may annoy others without arguing about manners.

Correct answer: Gas bubbles that burst in the joint fluid

The passage states directly that the popping sound comes from gas bubbles bursting in the joint fluid, which it calls a harmless process. It never names bones or tendons as the source of the sound, and it reports that research finds no link between knuckle cracking and arthritis.

Correct answer: Reassuring and factual

The author lays out research calmly and ends by telling readers the habit poses no proven danger, a reassuring tone built on facts. Nothing in the passage sounds alarmed, the misconception is corrected without ridicule, and the brief remark that the habit may annoy others is not a scolding.

Correct answer: Chronological order

The signal words 'first,' 'next,' 'then,' and 'finally' walk the reader through the steps in the order they happen, which is chronological order. The steps are not ranked from most to least important, the passage gives instructions rather than tracing causes to their effects, and it layers green and brown materials together without comparing them.

Correct answer: Turn the pile over once a week

Layering comes 'next' in the sequence and turning the pile weekly comes 'then,' so turning is the step that follows layering. Choosing a shaded spot is the first step, using the finished soil is the last, and the passage never tells readers to add more scraps at this stage.

Correct answer: Opinion of how social media affects close relationships

Both passages discuss social media and personal relationships, but Passage 1 says it isolates people while Passage 2 says it connects families across distances, so they differ chiefly in their judgment of its effect. Neither passage cites research, both use the same plain, everyday style, and neither indicates a particular audience.

Correct answer: Social media shapes the way people relate to each other.

Passage 1 says social media pulls people apart and Passage 2 says it brings distant families together, so both treat it as a real influence on relationships even though they judge that influence differently. Weakened family bonds and a preference for face-to-face talk reflect only Passage 1's view, which Passage 2 does not share, and the claim that social media changes little contradicts both passages.

Correct answer: Data from similar cities where traffic fell after adding bike lanes

The argument claims that bike lanes will reduce traffic, so the strongest support is 'data from similar cities where traffic fell after adding bike lanes', which shows traffic actually falling in comparable cities once they added lanes. 'A study showing that towns saved money after choosing bike lanes over new roads', 'a survey finding most residents want more bike lanes', and 'comments by residents who think bike lanes would look attractive' may favor the lanes on cost, popularity, or appearance, but none of them shows any effect on traffic.

Correct answer: It states its predictions without supporting evidence.

The columnist predicts less congestion and faster commutes but offers no data, examples, or sources to support those predictions, so the lack of evidence is the central weakness. The passage contains no statistics, its two claims are consistent with each other, and it never mentions opponents of bike lanes.

Correct answer: Fresh and original

Pairing chili peppers with chocolate surprised the guests because the idea was new to them, so 'novel' here means fresh and original. The noun sense of the word, a long work of fiction, does not fit, and nothing in the sentence points to cost or to a familiar, traditional dish.

Correct answer: Sea otters are recovering under protection, helping kelp forests return.

The passage moves from the otters' near extinction to their protected recovery and then to the kelp forests they help restore, so the best summary links the otters' return to the return of the kelp. Kelp regrowth is a result of the otters' recovery rather than its cause, the hunting history is only background, and the passage credits protection, not any change in the value of fur, for the recovery.

Correct answer: Shrink as the urchin population grows

Otters eat the sea urchins that destroy kelp, so without otters the urchins would multiply and the kelp would decline. Otters do not eat kelp themselves, but they control the animals that do, so the forests would neither stay the same nor spread, and the passage says nothing about water temperature.

Correct answer: A concluding generalization drawn from the case of the otters

The sentence opens with 'thus' and widens the otter story into a rule about ecosystems in general, so it works as a generalization drawn from the example. It does not dispute anything said about kelp, it is not itself a specific case, and it defines no term.

Correct answer: To persuade readers to start composting at home

The passage opens by urging readers to compost a banana peel and closes by saying anyone can make a difference with a small bin, so its main purpose is to persuade. The methane facts support that appeal rather than serve as the topic, the passage never says landfills are running out of room, and it encourages readers instead of scolding them.

Correct answer: It cuts methane emissions and turns the scraps into rich soil.

The passage says scraps rotting in landfills release methane, while composting at home turns the same scraps into rich soil and cuts emissions; those are the two advantages it names. It makes no comparison of costs, never says the bin traps gas, and mentions no law or trash fees.

Correct answer: Strong in effect

The passage calls methane a potent greenhouse gas, meaning one that is strong in its warming effect. Here the word does not mean poisonous or plentiful, and its sense of convincing applies to arguments, not to gases.

Correct answer: Year-round schooling reshapes the school calendar and remains controversial.

The passage explains that year-round schooling spreads the same number of days across the calendar, gives the supporters' case and the critics' case, and notes that the debate continues, so its central claim is 'year-round schooling reshapes the school calendar and remains controversial.' Only the supporters would say 'year-round schooling reduces summer learning loss and should be widely adopted.' Only the critics would say 'year-round schooling raises costs and makes summer vacations hard to plan.' And because the passage says the school year does not get longer, it rules out 'year-round schooling adds days to the school year and gives students shorter breaks.'

Correct answer: Laying out the opposing arguments in the debate

After one sentence defining year-round schooling, the passage gives the supporters' argument, then the critics' objections, and ends by noting that the debate continues, so it works by 'laying out the opposing arguments in the debate'. It is not 'narrating how school calendars have changed over time', since it tells no history; not 'explaining step by step how a year-round calendar works', since its definition is not a process; and not 'citing research findings that support one side of the issue', since it cites no research and favors neither side.

Correct answer: Vacations get harder to plan, and summer cooling costs more.

The critics' objections are that families struggle to plan vacations and that buildings cost more to cool in summer. Shorter, more frequent breaks and an unchanged number of school days simply describe the schedule, and reduced summer learning loss is the supporters' argument.

Correct answer: Held firmly in place

The sailors tied the boat to the dock and it did not drift as the waves grew, so 'fast' here means held firmly in place. The senses of speed, of abstaining from food, and of a clock running ahead of the correct time do not fit a boat tied to a dock.

Correct answer: Sleep is an active process that keeps the brain healthy.

The passage says sleep is not merely rest but active maintenance, then describes two jobs the brain does during deep sleep, clearing waste and strengthening memories. Treating waste clearance as the main job leaves out the work on memory, describing sleep as a shutdown contradicts the first sentence, and the passage never says that waste is what brings on sleep.

Correct answer: A decline in mental sharpness

The last sentence says skipping sleep harms mental sharpness and long-term learning, so a decline in sharpness is the likely result. Waste clearance and memory strengthening happen during deep sleep, so skipping sleep would slow them rather than improve them, and the passage says nothing about physical strength.

Correct answer: Dispute the notion that sleep is simply passive rest

In the opening sentence, the word 'merely' marks the view the author rejects, that sleep is nothing beyond passive rest, and the rest of the passage describes the active work the brain does. The author does not reduce sleep to a chance to rest, does not downplay its role in brain health, and argues that skipping sleep harms the brain.

Correct answer: The second sentence describes a result of the first.

Closing the bridge is what forced commuters onto a longer route, so the second sentence describes a result of the first. It gives no reason for the repairs, and it neither repeats nor contradicts the first sentence; it adds what happened because of the closure.

Correct answer: Volunteer firefighters give many rural towns protection they would otherwise lack.

The passage stresses that volunteers make up most rural fire crews, serve on top of their regular jobs, and provide the only fire protection many small towns have, so the best summary is 'volunteer firefighters give many rural towns protection they would otherwise lack.' The training schedule is a single detail, as in 'volunteer firefighters in rural towns train on nights and weekends around their jobs.' The passage never says 'volunteer firefighters in many rural towns are being replaced by paid fire crews.' It describes volunteers leaving work to answer alarms, not 'volunteer firefighters often quit their regular jobs to protect rural towns full time.'

Correct answer: Stress that small towns depend heavily on volunteers

The final sentence says that without volunteers many small towns would have no fire protection at all, which drives home how much those towns rely on them. It says nothing about volunteers leaving for cities, about paying them, or about how often fires break out.

Correct answer: Housing

Housing takes 40 percent of the budget, twice the next-largest category, food at 20 percent. Transportation takes 15 percent and savings 10 percent, so neither comes close.

Correct answer: 35%

Food is 20 percent and transportation is 15 percent, so together they account for 20 + 15 = 35%. Adding the other category's 15 percent as well gives 50%, combining the two largest categories, housing and food, gives 60%, and pairing housing with transportation instead of food gives 40 + 15 = 55%.

Correct answer: Weigh both the conservation gains and the welfare concerns

A balanced view takes in both arguments: the conservation work credited to zoos in Passage 1 and the concern for animals in captivity raised in Passage 2. Siding with either passage keeps only one side of the issue, and setting both aside throws away the very arguments the reader needs to weigh.

Correct answer: Wild animals fare better in nature than they do in captivity.

Passage 2 says no enclosure can replace the freedom of a natural habitat and that captivity stresses many animals, which rests on the assumption 'wild animals fare better in nature than they do in captivity.' Passage 2 never disputes that zoos breed endangered species for release, so it does not assume 'zoos fail to breed endangered animals for release into the wild.' It rules out any enclosure as a substitute for the wild, so it does not assume 'zoo animals would be content if their enclosures were larger.' It says nothing about money, so it does not assume 'zoos value the money their animals bring in more than animal welfare.'

Correct answer: To hold back or limit

A dam that checks a river's flow and prevents the floods that once swept the valley is holding that flow back, so 'check' here means to restrain or limit. The dam does not inspect the river, mark anything as done, or hand the water over for safekeeping; those are other senses of the word.

Correct answer: To explain the way the Dewey Decimal System sorts library books

The passage walks through how the system works, from number ranges for major fields to decimals for finer topics to the result that related books sit together, so its purpose is to explain how the system organizes books. It makes no case for replacing other systems, draws no comparison with shelving by author, and gives no history of how the system was created.

Correct answer: It places related books side by side so readers can locate them.

The last sentence says the structure lets readers find related books shelved together, so the benefit is 'it places related books side by side so readers can locate them.' The passage never mentions doing without a librarian, so it does not support 'it lets readers find books by themselves so they can avoid asking a librarian.' The system sorts by subject rather than by author, which rules out 'it sorts the books by author so readers can spot favorite writers.' Nothing ties the numbers to how often books are borrowed, which rules out 'it ranks books by checkouts so readers can spot popular titles.'

Correct answer: Coral reefs are small but vital to marine life, and warming seas now endanger them.

The passage contrasts the reefs' tiny share of the ocean floor with the quarter of marine species they support, then explains how warming water causes bleaching that can kill them, so its main idea is 'coral reefs are small but vital to marine life, and warming seas now endanger them.' Bleaching is only one supporting detail, as in 'coral reefs turn white as they expel their algae, but repeated bleaching can kill them.' Reefs cover less than one percent of the ocean floor, which rules out 'coral reefs cover vast stretches of seafloor, so most sea creatures live on them.' The algae feed the corals rather than harm the life around them, which rules out 'coral reefs are threatened mainly by algae, which harm the fish around them.'

Correct answer: To push out by force

Rising temperatures cause the corals to push out the algae that feed them, which turns the corals white, so 'expel' here means to force something out. Its senses of dismissing a student from school, banishing someone from a country, and breathing out air do not fit corals and algae.

Correct answer: Endanger large numbers of marine species

Reefs support about a quarter of all marine species, so losing them would endanger a great many of those species. The small area reefs cover does not make the loss minor, the passage has warming cause bleaching rather than reef loss cause warming, and nothing suggests the expelled algae would spread.

Correct answer: Once

'Once' signals time order: after the rain stopped, the game started again. 'Whereas' sets up a contrast between two facts and 'provided' sets up a condition, neither of which fits a sentence reporting what happened, and 'despite' is a preposition that cannot introduce a clause with its own verb (we say 'despite the rain', not 'despite the rain stopped').

Correct answer: Enthusiastic and supportive

The author answers the critics, credits the space program with everyday technology and urges readers to fund the work proudly, so the attitude is enthusiastic support. The skeptics are mentioned only to be rebutted, and the author takes a clear side rather than staying indifferent or torn.

Correct answer: Everyday technology developed by the space program

The author's evidence is satellite technology born from the space program that now guides cars, forecasts weather and connects phones. The line about every dollar returning value is a claim backed by no figures, and the passage cites no astronauts and no discoveries on other planets.

Correct answer: The overlooked benefits that space technology provides daily

Critics 'overlook its quiet gifts', and the author then names them: satellite technology that guides cars, forecasts weather and connects phones every day. 'Quiet' means unnoticed rather than silent or secret, and the 'gifts' are benefits, not donations.

Correct answer: City D

City D's 60 percent is the highest rate in the table, ahead of City B at 50, City C at 35 and City A at 25 percent.

Correct answer: 25 percentage points

City B recycles 50 percent and City A 25 percent, so the gap is 50 minus 25, or 25 percentage points. Using City D instead of City B gives 35, adding the two rates gives 75, and 100 is the relative increase (25 is 100 percent of 25), not a difference in percentage points.

Correct answer: Expectation can cause genuine bodily changes, which complicates drug testing.

The central point is that expectation can trigger genuine changes in the body, which is why doctors must account for it when testing new drugs. The passage denies that the pain was imaginary, never suggests replacing drugs with placebos, and the relief reported in some studies is a supporting detail rather than the main idea.

Correct answer: To cause something to happen

In 'expectation can trigger genuine changes in the body', trigger means to cause or set off those changes. Firing a gun, detonating an explosive and stirring up painful memories are other senses of the word that do not fit a sentence about bodily changes.

Correct answer: Because expectation alone can produce real drug-like effects

The passage says expectation can trigger genuine changes in the body, so improvement during a trial might come from belief rather than the medicine, and doctors must separate the two. It does not say patients exaggerate their relief, that sugar pills cause side effects, or that drugs work best in trusting patients.

Correct answer: To encourage readers to give tai chi a try

The passage speaks to the reader directly, praises the benefits of tai chi and ends with 'Give it a try', so its purpose is to persuade. It says tai chi does not strain the body, mentions balance only as one benefit without explaining how, and never brings up running.

Correct answer: People of almost any age or fitness level

The passage states that people of nearly any age or fitness level can practice tai chi, so 'People of almost any age or fitness level' is correct. 'People young and fit enough for any strenuous exercise' sets a condition the passage rules out, since tai chi is gentle and does not strain the body; 'People already trained in its movements by an instructor' and 'People already practicing it to relieve stress' add requirements (an instructor, earlier practice) that the passage never mentions.

Correct answer: Cause and effect

Maria's month of nightly study explains her top score: the first sentence gives a cause and the second its effect. No problem is posed and solved, nothing is compared, and the second sentence does not answer a claim made in the first.

Correct answer: Deep-sea animals use self-made light in several ways to survive.

The passage describes several survival uses of self-made light: luring prey, confusing predators and escaping in glowing clouds. Luring prey is one of those uses rather than a summary of them all, mates are never mentioned, and the flashes confuse predators instead of giving animals away to them.

Correct answer: To attract

Fish use light to lure prey, that is, to attract it toward them. Recalling a hawk is the falconer's sense of the verb, and light that frightened prey away or blinded it would not draw the prey toward them.

Correct answer: Releasing glowing clouds to get away

The passage says certain squid release glowing clouds to escape. Luring prey and flashing to confuse predators are uses it gives to fish, and attracting mates is not mentioned at all.

Correct answer: Word choice shapes how readers see the same event

Writer 1 presents the storm as a welcome rain that revived gardens, while Writer 2 presents it as a violent downpour that flooded streets, so the difference shows that 'Word choice shapes how readers see the same event'. 'At least one of the writers is misreporting how badly the streets flooded' is wrong because both accounts can be true at once; 'The writers must have seen two different storms' is wrong because nothing suggests two storms; and 'Darker descriptions of storms tend to be the more reliable ones' is wrong because neither tone is shown to be more reliable.

Correct answer: The writers described different effects of the storm.

Writer 1 stresses how the rain revived the gardens after a drought, while Writer 2 stresses the flooding and power loss, so each described a different effect of one storm. Nothing suggests either account exaggerates, nothing suggests either writer mixed up two storms, and both read as firsthand reports.

Correct answer: Water flowing in one direction

Swimmers are told to stay near shore because the current could pull them out to sea, so here current means water flowing in one direction. Electric current, and the adjective senses of belonging to the present or being widely accepted now, do not fit a force that can carry swimmers away.

Correct answer: Very little of Earth is left unmapped, but the deep ocean remains poorly charted.

The passage moves from old maps with blank spaces to today's nearly complete satellite mapping, then ends on the exception, so 'Very little of Earth is left unmapped, but the deep ocean remains poorly charted.' states the main idea. 'Old maps left blank spaces, but the mapmakers sometimes added warnings of monsters.' is only a supporting detail about the past; 'The surface of the Moon is less well charted than the deep ocean.' reverses the passage, which says the ocean is less charted than the Moon; and 'Old maps, honest about the limits of knowledge, were better than modern satellite maps.' ranks old maps above modern ones, which the passage never does.

Correct answer: Point out a surprising gap in what has been mapped

After saying satellites have mapped nearly every inch of Earth, the author turns with 'Yet' to the deep ocean, pointing out a surprising gap that remains. The sentence gives no reason the ocean is unmapped, makes no case for funding, and uses the Moon only as a point of comparison.

Correct answer: Surprising and notable

The word 'yet' and the comparison with the Moon show that the author finds it surprising that the deep ocean is still so poorly charted. Nothing in the tone suggests alarm or hope, and the author plainly does not treat the gap as ordinary.

Correct answer: A contrast of past and present that ends with a notable exception

The passage contrasts old maps, with their honest blank spaces, against today's satellite maps, then closes with the exception of the deep ocean. It proposes no solution or action, tells no personal story, and does not define a term and illustrate it.

Correct answer: Yawning may cool the brain as well as signal tiredness.

The passage sets the common belief that yawning signals boredom or tiredness beside the scientific view that it cools the brain, so 'Yawning may cool the brain as well as signal tiredness.' is the central idea. 'Yawning is mainly the brain signaling boredom or tiredness.' repeats the assumption the passage questions, since boredom may simply be when yawns are most noticed; 'Boredom overheats the brain, and yawning is just the result.' invents a link the passage never makes; and 'By warming the brain, yawning may keep tired people alert.' reverses the passage, since a yawn draws in cooler air and lowers brain temperature.

Correct answer: Give a scientific explanation challenging popular belief

The passage opens with what many assume about yawning and then presents the scientific view that it may cool the brain, so its purpose is to challenge a popular belief with a scientific explanation. It argues against the boredom view rather than defending it, urges no one to yawn more, and aims to explain rather than to entertain.

Correct answer: Pulls inward

A deep yawn draws in cooler air, that is, pulls the air inward. A train that draws in arrives at a station, a cause that draws people in gets them to take part, and an artist who draws in a detail adds it to a sketch; none of these fits air taken in by a yawn.

Correct answer: Yawns pull in cool air and boost blood flow to lower brain temperature.

The cooling claim rests on the mechanism the passage describes: a deep yawn draws in cooler air and increases blood flow, lowering the brain's temperature. The common assumption about boredom and the remark about when yawns are noticed concern boredom, not how a yawn cools the brain, and contagious yawning is never mentioned.

Correct answer: However

'However' signals the contrast between a plan that looked perfect and a plan that failed. 'Therefore' would present the failure as a result of looking perfect, 'also' would merely add a point, and 'unless' would set up a condition, which makes no sense here.

Correct answer: Modern libraries offer a wide range of useful services beyond books.

The passage lists tools, instruments, seeds, internet access, job help and shelter to show that libraries now serve the whole person, so 'Modern libraries offer a wide range of useful services beyond books.' is the main idea. 'Some modern libraries now lend tools, musical instruments and garden seeds.' is only one supporting example; 'Modern libraries have shifted their focus away from lending books.' is wrong because libraries still serve readers; and 'Modern libraries matter less now that people find information online for free.' is never suggested.

Correct answer: Busy centers of community life

Libraries have become community hubs, busy centers where people gather for many services. The middle of a wheel, a device linking computers and an airport that an airline routes flights through are other meanings of hub that do not describe a library.

Correct answer: A summary that concludes the passage

After listing what libraries now lend and offer, the author ends by drawing those examples together: the modern library serves the whole person. That sentence sums up the passage rather than adding another example, states the author's own view rather than a claim to be rejected, and is not quoted from anyone.

Correct answer: Homework in elementary school should be kept light.

The author argues that homework should be assigned sparingly in elementary school to protect time for play and rest. Stopping homework altogether goes beyond 'sparingly', the cited studies find little link between heavy homework and early achievement, and the passage says nothing about how much homework older students need.

Correct answer: Studies that found little link between heavy homework and early success

The author's evidence is research: studies find little link between heavy homework and achievement in the early grades. The passage cites no parent surveys, no test results from schools that dropped homework, and no stories from teachers or parents.

Correct answer: Logical and persuasive

The author makes a clear case for lighter homework and supports it with reasons and research, so the tone is logical and persuasive. The writing is calm rather than angry, takes a side rather than staying neutral, and argues from evidence rather than from sentiment.

Correct answer: Student 3

Student 3 rose from 50 to 85, a gain of 35 points, compared with 20 points for Student 1 (60 to 80) and 5 points for Student 2 (70 to 75), so the gains were not equal.

Correct answer: The three students raised their scores after being tutored.

Every after-tutoring score is higher than the matching before score (60 to 80, 70 to 75 and 50 to 85), so 'The three students raised their scores after being tutored.' is best supported. 'After tutoring, students who started highest gained the most.' is wrong because Student 2 started highest but gained least; 'The three students gained about the same number of points.' is wrong because the gains of 20, 5 and 35 points were far from equal; and 'Tutoring will raise the grades of other students who receive it.' is wrong because three students are too few to predict results for others.

Correct answer: Free of serious defects

A bridge declared structurally sound, able to carry traffic for decades, is free of serious defects. Sound can also describe deep, undisturbed sleep, name a noise, or name a narrow channel of the sea, but none of these fits the condition of a bridge.

Correct answer: Slow cameras, not sad moods, explain the serious faces in old portraits.

The passage traces the unsmiling faces in early portraits to exposures that took hours, then states that those faces reflect technology rather than gloomy personalities. The idea that people were gloomy is the one the passage rejects, it never mentions what photographers thought of smiling, and the arrival of smiles with faster cameras is a supporting detail.

Correct answer: More likely to include smiles

The passage says smiles slowly appeared in pictures as cameras grew faster, so shorter exposures made smiling portraits more likely. Faster exposures reduce blurring rather than add to it, the stiff poses belonged to the slow early cameras, and cost is never discussed.

Correct answer: That the stern faces in old photos show unhappy personalities

The final sentence says the serious faces of old photos reflect technology, not gloomy personalities, correcting the belief that people back then were unhappy. The passage itself says a grin held that long would blur, and it says nothing about what photographers wanted or what portraits cost.

Correct answer: House spiders are largely harmless allies against pests.

The passage answers the common fear of spiders by showing that most house spiders are harmless and that they eat insects, including the flies and mosquitoes that carry disease, so the main idea joins both points. Eating hundreds of insects a year is one supporting detail, not the whole point. The disease comes from the insects rather than the spiders, and the passage gives no reason for the fear, least of all spiders hiding in corners.

Correct answer: Persuade readers to think more kindly of house spiders

The passage starts from the usual fear of spiders and then gives reasons to let them stay, so its purpose is to 'persuade readers to think more kindly of house spiders'. It does not 'warn readers to fear house spiders more than flies' (the flies and mosquitoes carry the disease, and spiders eat them), 'teach readers how to keep house spiders out of their homes', or 'explain to readers how house spiders build their webs'.

Correct answer: Supportive partners

Spiders are called 'quiet allies in the home' because they help people by eating pests, so here the noun means supportive partners. The treaty sense applies to nations, and the passage presents spiders as helpers, not as enemies or pests.

Correct answer: The trail is steep for the first mile

The text's 'climbs steeply for the first mile' and the tightly spaced contour lines at the start describe the same steep opening section. Widely spaced lines near the lake show gentle ground, the trail rises toward the lake rather than dropping to it, and neither source says how hard the hike is for beginners.

Correct answer: It is visual support for what the text says about the slope.

Tightly spaced contour lines mark steep ground and widely spaced lines mark gentle ground, so the map note matches the text: a steep first mile that levels off near the lake. The note does not contradict the text, move the steep section to the lake, or add new facts about the lake itself.

Correct answer: Quick to learn

Leo grasps new concepts faster than anyone in the class, so 'bright' describes his mind: intelligent and quick to learn. Giving off light, being brilliant in color and being cheerful and lively are real senses of the word, but none of them fits a student praised for understanding quickly.

Correct answer: Trees offer many practical benefits for nature and the economy.

After noting that trees do more than give shade and beauty, the passage lists soil protection, cleaner air and economic value, so the main idea is that 'trees offer many practical benefits for nature and the economy.' The passage moves beyond shade and beauty rather than putting them first, which rules out 'trees are prized mainly because they give shade and beauty.' Erosion control is only one of the benefits, and the passage never ranks it highest, which rules out 'trees matter most because their roots keep soil from washing away.' The dollar figure is a living tree's benefits over its lifetime, not a lumber price, which rules out 'trees are worth many thousands of dollars each when sold as lumber.'

Correct answer: They stop heavy rainstorms from washing the soil away.

The passage says the roots 'hold soil in place, preventing erosion during heavy rains.' Filtering air pollutants is the work of the leaves, shade is mentioned only as an obvious benefit of trees in general, and the passage does not say that roots prevent flooding.

Correct answer: Prepare readers for the additional benefits of trees

'Do more than provide shade and beauty' grants those familiar benefits and tells readers that others are coming, which the rest of the passage supplies (erosion control, cleaner air and economic value), so the sentence serves to 'prepare readers for the additional benefits of trees'. It does not 'praise shade and beauty as what matters most about a tree' or 'dismiss shade and beauty as having little value', and it does not 'rank the benefits of trees by their importance'.

Correct answer: It features a 40-foot fossil skeleton discovered in 2019.

The skeleton's length and the year it was found can be checked against records, so that sentence states a fact. Calling the exhibit the best attraction in the state, calling the lighting dramatic and the displays stunning, and saying visitors should not miss it are all judgments that people could disagree with.

Correct answer: Bees dance to tell the hive where to find food.

Every sentence of the passage explains how the waggle dance tells other bees the direction and distance of food, so that is the main idea. The dancer is a bee returning from the flowers rather than a guide for lost bees, the passage mentions no danger, and the sun serves as the reference point for the dance's angle, not as its message.

Correct answer: The direction of the food relative to the sun

The passage says the angle of the dance 'points toward the sun's position,' so the angle shows the direction of the food measured against the sun. The dance as a whole also signals distance, but the passage ties the angle to direction, and it says nothing about the sun's height or the height of the flowers.

Correct answer: The dance that bees use to pass on directions

The passage calls the waggle dance a 'silent language' because it passes on directions to food without any sound. Buzzing is a sound, the passage never mentions scent, and the sun is the reference point that the dance's angle points toward rather than the language itself.

Correct answer: Moreover

'Moreover' adds a further point in the same direction, joining a third good quality (great taste) to the first two (quick and cheap). 'Conversely' signals a reversal or contrast, 'accordingly' signals a result, and 'meanwhile' signals that two things happen at the same time, so none of them shows addition.

Correct answer: How many dentists were asked and how were they selected?

A figure like 'nine out of ten' means little until you know how large the sample was and whether the dentists were picked fairly, so the question that tests the claim directly is 'how many dentists were asked and how were they selected?' The other questions say nothing about whether the survey behind the claim can be trusted: 'do dentists advise patients to brush and floss after meals?' asks about brushing advice, 'how many stores carry the toothpaste compared with other brands?' asks about sales, and 'does the toothpaste come in a flavor that children enjoy?' asks about taste.

Correct answer: The company had paid the ten dentists it surveyed for the ad

A survey of just ten dentists, each paid by the company, is too small and too biased to support the claim, so the claim would be weakest if 'the company had paid the ten dentists it surveyed for the ad'. Learning that 'the company surveyed over a thousand dentists in all fifty states' would strengthen the claim, and neither 'the toothpaste costs a dollar more than the two leading brands' nor 'the toothpaste is stocked by two of the largest drugstore chains' has anything to do with what dentists recommend.

Correct answer: A thing secretly placed to mislead

Detectives think the evidence was put there on purpose to frame an innocent suspect, so a 'plant' here is something secretly placed to mislead investigators. The word can also mean a living organism that grows in soil, a factory, or the machinery a factory runs on, but none of those fits evidence left at a scene.

Correct answer: The printing press changed the world by spreading ideas widely.

The passage says the press did more than make books cheaper: by spreading ideas quickly it fueled revolutions and let ordinary people read for themselves, so its main idea is that the press transformed society. Cheaper books is the point the passage moves beyond, religion is one of three fields it names, and the press freed readers from a few authorities rather than giving those authorities control.

Correct answer: A sweeping claim meant to stress the importance of the press

With the words 'in a real sense' the author signals that the line is not meant literally; it is a sweeping statement made to stress how much the press mattered. No date or record could prove that the modern world began with movable type, the line is not attributed to any expert, and the author agrees with it rather than rejecting it.

Correct answer: Limited to what a few authorities chose to share

The passage says that after the press, ordinary people 'could read for themselves rather than rely on a few authorities,' which implies that before it, written ideas reached most people through those few authorities. Ideas crossing borders and people reading for themselves describe the world after the press, and books became cheaper after it, not before.

Correct answer: Rivers gradually bend as water moves soil from outer banks to inner ones.

The passage explains that water wears away the outer bank of each curve and leaves sediment on the inner bank, slowly exaggerating the bends, so the main idea is that rivers curve through erosion and deposition over time: 'rivers gradually bend as water moves soil from outer banks to inner ones.' Sediment builds up on the inner banks, not the outer ones, which rules out 'rivers curve because sediment slowly builds up on their outer banks.' The crescent-shaped lake is one result of the process rather than its main point, which rules out 'rivers leave behind crescent-shaped lakes when loops pinch off.' The passage describes slow, patient change, not a sudden flood, which rules out 'rivers leave their straight paths when a sudden flood carves a new channel.'

Correct answer: Leaves behind in a layer

Water that slows on the inside of a bend drops the sediment it carries, so 'deposits' means leaves behind or lays down. Putting money in a bank, paying a first installment and handing something over for safekeeping are other real senses of the word, but water does none of these with sediment.

Correct answer: When a river loop is cut off from the main channel

The passage says that 'a loop may pinch off, leaving a crescent-shaped lake behind,' so the lake forms when a loop is cut off from the rest of the river. Wearing away the outer bank and filling in the inner bank are the steps that exaggerate a bend before that happens, and the passage does not mention floodwater spilling into a valley.

Correct answer: Steady and gradual

'Slow' and 'patient' describe work that goes on little by little without stopping, so the author sees the process as steady and gradual. Nothing in the phrase suggests sudden force, the personification does not give water a plan, and the tone admires the process rather than condemning it.

Correct answer: Sign languages are independent languages with a grammar of their own.

The passage argues that sign languages are full languages with their own grammar, developed naturally by deaf communities, rather than gestures that copy speech. It rejects the idea that signing is spoken language acted out, its example shows two English-speaking countries with different sign languages, and it credits deaf communities, not teachers, with creating them.

Correct answer: Show that sign languages do not follow the local spoken language

The United States and Britain both speak English, yet their sign languages differ in structure, so the author mentions the difference to 'show that sign languages do not follow the local spoken language'. The example works against the idea that sign languages copy English, so it cannot 'show that sign languages are not truly distinct from English', and the passage says nothing that would 'show that sign languages are harder to learn in Britain than in America' or 'show that sign languages spread from America to Britain over time'.

Correct answer: To brush aside as unimportant

To dismiss sign languages 'as mere pantomime' is to brush them aside as unimportant, which the author says misunderstands their richness. Firing a worker, letting a class go and throwing a case out of court are real senses of the word, but they do not fit a sentence about how people judge a language.

Correct answer: Lifts productivity but reduces collaboration

Article 1 reports that people finish more work at home, and Article 2 reports that teams who never meet lose spontaneous ideas, so a balanced reader sees a trade-off: remote work 'lifts productivity but reduces collaboration'. Saying it 'cuts productivity and weakens collaboration' ignores Article 1, saying it 'boosts productivity and improves collaboration' ignores Article 2, and saying it 'lowers productivity but strengthens collaboration' reverses both articles.

Correct answer: Splitting time between home and the office could offer focus and teamwork.

One article praises focused work at home and the other values ideas that spark in shared spaces, and a schedule split between the two could keep both, so the statement that reconciles them is 'splitting time between home and the office could offer focus and teamwork.' Two of the other statements each restate only one side: 'working at home could let people finish more tasks without office interruptions.' repeats Article 1, and 'teams in an office come up with more ideas than teams at home do.' repeats Article 2. A full-time return to the office simply gives up Article 1's benefit, which rules out 'many firms now require home workers to return to the office full time.'

Correct answer: Gentle and kind

The nurse's care calms a frightened child into sleep, so 'tender' here means gentle and kind. The word can also mean sore to the touch, young (as in 'a tender age') or soft enough to chew easily, as with meat, but none of those describes a nurse's care.

Correct answer: Laughter benefits people in physical as well as social ways.

The passage lists physical benefits (relaxed muscles, lower stress hormones, a brief immune boost) and a social one (stronger bonds), while warning that laughter is no cure-all, so the main idea is that it offers real physical and social benefits. Claiming it heals better than medicine ignores that warning, and the immune boost and the lack of cost are single details rather than the main point.

Correct answer: Make clear that laughter helps but has its limits

'While no cure-all' concedes that laughter cannot fix every problem before the author states its real benefits, so the author wants to 'make clear that laughter helps but has its limits'. The qualifier limits the claim without denying the benefits, so the author does not 'admit that laughter feels good but does little for health', does not 'warn readers that laughter can sometimes cause harm', and does not 'stress that laughter helps more than medicine does'.

Correct answer: Draws people closer to one another

The passage names one social benefit: laughter 'strengthens social bonds, drawing people closer.' Relaxing muscles, lowering stress hormones and briefly boosting the immune system are the physical benefits it lists.

Correct answer: Consequently

The school delayed its opening because the road was icy, so the second clause is a result of the first and 'consequently' fits. Using 'nevertheless' would set the delay against the ice as a contrast, 'specifically' would present the delay as a closer detail of the ice, and 'similarly' would treat the two facts as alike.

Correct answer: Wetlands give valuable protection from floods and pollution.

The passage describes wetlands soaking up floodwater and filtering pollutants, then warns that draining them removes this free protection, so the central idea is their value against floods and pollution. Soaking up floodwater is one of the two services, the passage argues against draining, and wetlands hold water back from towns rather than sending it there.

Correct answer: Soak up and hold water in large amounts

The next sentence explains the comparison: during heavy rains wetlands 'soak up floodwater,' the way a sponge takes in and holds water. The passage says nothing about how wetlands feel underfoot, whether they are full of holes, or whether they float; those details belong to the sponge, not to the point being made.

Correct answer: Worse flooding and dirtier rivers

Wetlands soak up floodwater and filter pollutants, so draining them would remove both services, leaving towns open to more flooding and rivers to dirtier water. Any choice that predicts fewer floods or cleaner water reverses one or both of those effects.

Correct answer: To take out impurities

Wetlands 'filter pollutants, cleaning water before it reaches rivers,' so 'filter' here means to take impurities out. Passing through slowly, becoming known bit by bit (as news filters out) and arriving a few at a time (as a crowd filters in) are real senses of the word, but in each of them something moves along instead of being removed.

Correct answer: Higher scores might come from something other than breakfast

The critic notes that wealthier families are more likely to provide both breakfast and tutoring, so family wealth, or the tutoring it pays for, could explain the results: 'higher scores might come from something other than breakfast'. The critic does not claim that 'tutoring is proven to help students more than breakfast does', does not say that 'wealthy students skip breakfast more often than other students' (their families are more likely to provide it), and does not suggest that 'breakfast eaters might also sleep longer than their classmates' (sleep is never mentioned; the second factor the critic names is family wealth and the tutoring it buys).

Correct answer: The correlation does not prove breakfast raised scores

By pointing to a second difference between the groups, the critic shows that 'the correlation does not prove breakfast raised scores': the link may not reflect cause and effect. The critic offers tutoring as a possible explanation without proving it, so 'tutoring is the proven cause of the higher scores' goes too far, and the objection is about what caused the scores, not that 'the tests were unfair to students from poorer families' or that 'the study did not include enough children from poor homes'.

Correct answer: To tackle a problem

The mayor plans to fix the housing shortage by approving permits, so 'address' here means 'to tackle a problem.' The word can also mean 'to direct a comment to someone', as when you address a question to a clerk; 'to call someone by a title', as when you address a judge as Your Honor; or 'to label a letter for delivery', as when you address an envelope. None of those senses fits a plan to fix a shortage.

Correct answer: What makes a desert is low rainfall, not sandy soil or heat.

The passage says a desert 'is defined by how little rain it receives, not by its temperature or surface,' so the best statement of the main idea is 'what makes a desert is low rainfall, not sandy soil or heat.' 'Parts of Antarctica count as deserts, though not hot ones.' is true, but it is one supporting example, not the main idea. 'A typical desert is sandy, though a few are not, like Antarctica.' repeats the common belief the passage corrects; the passage says many deserts are rocky or icy. 'Icy places count as deserts because of frozen ground, not dryness.' gives the wrong reason: Antarctica counts because it gets so little rain, not because of its frozen ground.

Correct answer: A place that is dry enough is a desert whether hot or cold

The passage defines a desert by 'how little rain it receives, not by its temperature or surface,' and then names Antarctica, so the example shows that 'a place that is dry enough is a desert whether hot or cold.' 'Temperature is the factor that decides whether or not a region is a desert' reverses the passage, which says temperature does not decide it. 'A cold region is more likely than a hot one to be a desert' compares cold and hot regions, which the passage never does. 'Antarctica is a desert because it is covered in a thick sheet of ice' gives the wrong reason; Antarctica counts because it is dry, not because of its ice.

Correct answer: Sum up the central point in a memorable way

The closing line repeats, in short and catchy form, the claim that dryness rather than sand defines a desert, so it serves to 'sum up the central point in a memorable way.' It does not 'introduce a new idea for the reader to consider', since dryness was the topic all along; it does not 'point to the flaw in a definition given earlier', since it agrees with that definition; and it does not 'give the reader an example of a dry place', since it names no place at all.

Correct answer: First powered flight

The earliest date on the timeline is 1903, the year of the first powered flight, so the answer is 'first powered flight.' 'First solo transatlantic flight' came later, in 1927, and 'the Moon landing' came last, in 1969. 'They happened in the same year' is not correct, because the three events have three different dates.

Correct answer: 66 years

Subtract the year of the first powered flight from the year of the Moon landing: 1969 - 1903 = 66, so the answer is '66 years.' '42 years' is the gap from the 1927 solo flight to the Moon landing, '24 years' is the gap from the first flight to the solo flight, and '56 years' is off by ten, a slip in the subtraction.

Correct answer: Money available for investment

The company needs money from investors to build factories, so 'capital' here means 'money available for investment.' The word can also mean 'the city where a government is based', as in a state capital; 'of the highest importance', as in a matter of capital importance; or 'punishable by death', as in a capital crime. Only the money sense fits a company that needs funds to grow.

Correct answer: Octopuses are unusually clever and resourceful creatures.

Every sentence develops the opening claim that octopuses are 'remarkably intelligent for invertebrates,' so the main idea is 'octopuses are unusually clever and resourceful creatures.' 'Octopuses use their arms mainly to carry coconut shells for shelter.' stretches one example, the coconut shells, into the whole point. 'Octopuses show that most invertebrates are smarter than assumed.' contradicts the last sentence, which says few animals without backbones show such skill. 'Octopuses think with their arms, which can taste and touch on their own.' overstates a detail; the passage says the arms 'can act somewhat independently,' not that they think.

Correct answer: They solve puzzles and open jars.

Solving puzzles and opening jars are acts of problem solving, so the detail that best supports the claim is 'they solve puzzles and open jars.' 'They sense taste and touch through their arms.' and 'they have arms that can each move and act on their own.' describe how the arms sense and move, not how the animal thinks, and 'they have soft bodies and squeeze into small gaps.' describes its body. None of them shows intelligence.

Correct answer: Separately from the others

Each arm can act on its own, so 'independently' here means 'separately from the others.' The word can also mean 'free from rule by another nation', as when a former colony governs itself; 'with no financial aid from others', as when an adult lives independently; or 'free from outside bias or influence', as when a study is independently checked. Arms that move apart from one another fit only the sense of acting separately.

Correct answer: A claim supported by a series of examples

The passage opens with a claim, that octopuses are 'remarkably intelligent for invertebrates,' and then offers puzzles, jars and coconut shells as evidence, so its structure is 'a claim supported by a series of examples.' It is not 'a cause followed by a long chain of effects', because nothing in it causes anything else; not 'a series of events ordered by time', because the details are not arranged by time; and not 'a problem followed by a set of solutions', because it raises no problem to solve.

Correct answer: To share a few practical ways to reuse old coffee grounds

The passage opens with 'Don't toss those coffee grounds' and then lists garden and kitchen uses, so its purpose is 'to share a few practical ways to reuse old coffee grounds.' 'To explain how coffee grounds add nitrogen to garden soil' names one of those uses, not the purpose of the whole passage. 'To warn that coffee grounds can harm plants in a garden' reverses the passage, which says the grounds help a garden. 'To argue that coffee grounds should be sold as fertilizer' goes beyond the passage, which never mentions selling the grounds.

Correct answer: Add nitrogen to the soil and keep slugs away

The passage says used grounds 'add nitrogen to the soil and deter slugs,' so the answer is 'add nitrogen to the soil and keep slugs away.' 'Remove nitrogen from the soil and keep slugs away' reverses the nitrogen detail, since the grounds add nitrogen rather than take it away. 'Add nitrogen to the soil and draw slugs in' reverses the slug detail, since the grounds deter slugs rather than attract them. 'Remove nitrogen from the soil and draw slugs in' makes both mistakes.

Correct answer: A useful role once its main job is done

Grounds that go on to feed a garden or freshen a refrigerator after brewing have found 'a useful role once its main job is done', which is what 'second life' means here. The phrase can also suggest 'rebirth into a new body at death', 'an extra life in a video game' or 'a double life kept hidden from other people', but coffee grounds are not reborn, are not game characters and lead no hidden life.

Correct answer: Each person has distinct fingerprints that stay unchanged for life.

The passage says fingerprints 'never change throughout life' and can 'identify a single individual among billions,' so the main idea is 'each person has distinct fingerprints that stay unchanged for life.' 'Fingerprints are determined by the DNA each person inherits.' is contradicted by the twins, who share DNA but not fingerprints. 'Even identical twins, with the same DNA, have fingerprints that differ.' is a true detail, but it supports the main idea rather than stating it. 'Fingerprints can tell most people apart but not identical twins.' gets the twins backward: even identical twins have different fingerprints, so prints can tell them apart too.

Correct answer: Unique even among people with identical DNA

Identical twins share the same DNA yet have different fingerprints, so the example shows that fingerprints are 'unique even among people with identical DNA.' The twins rule out 'passed down through DNA even before birth', since shared DNA does not produce matching prints. 'Shared even by twins, like their genes' reverses the example, and 'hard to tell apart in twins, even for experts' misses its point: the passage uses the twins to show that their prints differ, not to compare how hard prints are to tell apart.

Correct answer: To come into existence

The ridges arise from random conditions in the womb, so 'arise' here means 'to come into existence.' The word can also mean 'to get up from a seat or bed', as in 'arise from your chair'; 'to rise up in revolt', as when a people arise against a tyrant; or 'to move upward through the air', as when mist arises from a lake. Ridges forming before birth fit the sense of coming into being.

Correct answer: Economic gain to be weighed against environmental risk

Passage 1 stresses the new jobs and Passage 2 the threat to the drinking water, so a reader of both should see 'economic gain to be weighed against environmental risk.' 'A clear economic gain with no serious environmental risk' ignores Passage 2. 'An environmental risk that economic gain would remove' claims that the jobs would cure the pollution risk, which neither passage says. 'An economic risk to be offset by environmental gain' swaps the two sides: the jobs are the economic gain and the runoff is the environmental risk.

Correct answer: Whether pollution-control technology could limit the runoff

The choice is between new jobs and a threat to the town's drinking water, so the most useful fact is 'whether pollution-control technology could limit the runoff': if the runoff can be stopped at the source, the town might gain the jobs without the harm. 'Whether the factory owner could win any awards for business success', 'how many more factories the same company could open abroad' and 'what color the outer walls of the new factory would be painted' say nothing about either the jobs or the water.

Correct answer: Solemn and grim in manner

A doctor delivering very serious news wears a look that is 'solemn and grim in manner', which is what 'grave' means here. As a noun, a grave is 'a place in which the dead are buried', and a grave accent is 'a slanted accent mark over a letter'; the old form 'graven' means 'carved or cut into stone'. None of those fits a facial expression.

Correct answer: New research is challenging the old advice about static stretching before a workout.

The passage reports that 'recent research questions static stretching' and that the old advice 'is being rethought,' so the main idea is 'new research is challenging the old advice about static stretching before a workout.' 'Holding a stretch for a long time may temporarily weaken the muscles before a workout.' is a supporting detail, not the main idea. 'Most coaches now tell their athletes not to warm up the body before a workout.' contradicts the passage, since trainers now recommend a dynamic warm-up. 'Held stretches are still the best way to get ready before a workout.' states the old advice that the research is calling into question.

Correct answer: A dynamic warm-up of light movement

The passage says 'many trainers now recommend a dynamic warm-up of light movement instead,' so the answer is 'a dynamic warm-up of light movement.' 'A static warm-up of long-held stretches' is the static stretching that trainers are moving away from. 'A warm-up of deep breaths at rest' and 'a fast warm-up of sprints' do not appear in the passage; resting breaths are not movement, and full-speed sprints are not light.

Correct answer: Widely trusted in the past but now in doubt

'Once seemed certain' means people used to treat the advice as settled, and the passage says it 'is being rethought,' so the advice was 'widely trusted in the past but now in doubt.' 'Firmly rejected long ago but now back in favor' reverses the order of events, and 'widely doubted in the past but now firmly settled' reverses the direction of the change. 'Trusted by experts but now ignored in practice' invents a split between experts and athletes that the passage never mentions.

Correct answer: Held motionless in a single position

Static stretching is set against a 'dynamic warm-up of light movement,' so 'static' here means 'held motionless in a single position.' The word can also name 'crackle heard on a poorly tuned radio', describe something 'charged with stored electricity', as in static electricity, or mean 'angry criticism or complaints', as in 'taking static from the boss.' None of those describes a way of stretching.

Correct answer: The patch is mostly fine bits of plastic, so prevention is crucial.

The passage replaces the image of a solid island with 'a vast soup of tiny plastic pieces' and ends by saying prevention 'may matter more than removing it,' so the main idea is 'the patch is mostly fine bits of plastic, so prevention is crucial.' 'The patch holds plastic so tiny that much of it cannot be seen.' is a true detail, not the main idea. 'The patch is a floating island of plastic, and crews could scoop it up.' repeats the island image the passage rejects. 'The patch is large, so crews should haul the plastic away now.' calls for the removal effort that the passage says matters less than prevention.

Correct answer: Fine bits scattered and mixed through the sea

A soup is a liquid with small pieces mixed all through it, and the passage describes 'tiny plastic pieces spread across the water,' so the image conveys that the plastic is 'fine bits scattered and mixed through the sea.' 'Clumped into one thick mass on the surface' describes the solid island the passage rejects. 'Carried by currents to the coast' adds a movement the passage never mentions; a soup suggests pieces mixed in place, not carried somewhere. 'Heated and thickened by the sun at the surface' takes the word 'soup' literally; the passage says nothing about heat.

Correct answer: Stop plastic at its source before it reaches the sea

The last sentence says that 'preventing plastic from entering the ocean may matter more than removing it,' so the author would most likely say the best response is to 'stop plastic at its source before it reaches the sea.' 'Send ships to skim floating plastic before it breaks apart' and 'use fine nets to catch the tiny pieces before they sink' are cleanup efforts, which the passage calls far harder and less important than prevention. 'Wait for scientists to study the plastic more before acting' has no support in the passage, which already draws its conclusion.

Correct answer: Enormous in size

The plastic soup is spread across a huge stretch of ocean, so 'vast' here means 'enormous in size.' It does not mean 'very thick in texture', which confuses the word with the image of soup; 'mostly empty of life', which mixes it up with words like 'barren'; or 'very hard to see', which describes the tiny pieces rather than the patch as a whole.

Correct answer: Venus and Earth are similar in scale but turned out very differently.

The passage opens by calling Venus and Earth 'nearly twins in size' whose 'fates could not be more different,' so the main idea is 'Venus and Earth are similar in scale but turned out very differently.' 'Venus grew hot because it is much larger in size than Earth.' contradicts the passage, which says the planets are nearly the same size. 'Venus became hot enough to melt lead because of a runaway greenhouse effect.' is a true detail but too narrow to be the main idea. 'Earth sits a bit closer to the Sun than Venus but stayed much cooler.' reverses the passage, which places Earth at a slightly greater distance from the Sun.

Correct answer: Heat trapped by its runaway greenhouse effect

The passage says 'a runaway greenhouse effect trapped heat on Venus,' so the answer is 'heat trapped by its runaway greenhouse effect.' 'Its greater distance from the Sun than Earth's' reverses the passage, which places Earth farther from the Sun. 'Volcanic activity beneath its surface' is never mentioned. 'Molten lead spread across its rocky surface' confuses a result with the cause: the surface grew hot enough to melt lead because of the trapped heat.

Correct answer: A broad lesson that the comparison teaches

After contrasting two planets of nearly the same size, the passage closes with a general statement about 'small differences,' so the sentence works as 'a broad lesson that the comparison teaches.' It is not 'a caution that the Earth may one day become like Venus', since it predicts nothing about Earth; not 'a summary of how the greenhouse effect warms Venus', since it says nothing about how the effect works; and not 'a challenge to the comparison made earlier', since it builds on that comparison rather than disputing it.

Correct answer: How events finally turn out

The planets' fates are how each one turned out, one scorched and one able to support life, so the word here means 'how events finally turn out.' It can also mean 'a power thought to decide what happens', name the Fates of Greek myth, 'goddesses said to spin threads of life', or mean 'deaths or terrible ends', as in 'met their fates,' but none of those fits two planets that simply developed differently.

Correct answer: Reading aloud helps children develop in ways that last for years.

The passage says reading aloud 'does more than entertain,' lists the skills it builds and ends with 'a lifetime habit,' so the main point is 'reading aloud helps children develop in ways that last for years.' 'Reading aloud mainly helps children learn words that they hear in stories.' picks out one benefit, vocabulary, as if it were the whole point. 'Reading aloud is mostly a way to entertain children at bedtime.' contradicts the first sentence. 'Reading aloud is the best way to turn children into readers.' makes a comparison the passage never makes.

Correct answer: To influence the way it turns out

A few minutes of bedtime reading can help decide whether a child grows into a reader, so 'shape' here means 'to influence the way it turns out.' The word can also mean 'to mold clay or wood into a new form', 'the outline of a physical object' or 'physical fitness or good health', as in 'in good shape,' but a habit is not molded by hand, has no outline and is not a state of health.

Correct answer: Small nightly routines can make a big difference over many years

The passage ends by saying that a few minutes of bedtime reading can build a habit that lasts a lifetime, so the author would agree that 'small nightly routines can make a big difference over many years.' 'Parents should read aloud to their children for at least an hour each night' goes beyond the passage, which speaks of a few minutes, not an hour. 'Children learn to read best when they read on their own' runs against the passage, which credits reading aloud with making eager readers. 'The warmth of a voice matters more than the stories themselves' ranks two benefits that the passage simply lists together.

Correct answer: For instance

The words after the blank, oranges and strawberries, are examples of fruits rich in vitamin C, so the transition is 'for instance.' 'In contrast' signals an opposing idea, 'consequently' signals a result and 'in addition' adds a separate point, and none of those relations links a general claim to its examples.

Correct answer: The notion that people use just a tenth of their brains is wrong.

The passage calls the ten-percent idea a 'myth,' cites brain scans showing activity across nearly all regions and ends by calling it 'simply false,' so the main idea is 'the notion that people use just a tenth of their brains is wrong.' 'Most people in fact use just a tenth of their brains during the day.' restates the myth the passage rejects. 'Different tasks light up different parts of the brain during the day.' is a supporting detail, not the main idea. 'People have hidden reserves in their brains that a little practice can unlock.' repeats the 'appealing idea of hidden mental reserves' that the passage calls false.

Correct answer: Images that record almost the whole brain at work

The author answers the myth with evidence that 'brain scans show activity across nearly all regions over the course of a day,' so the evidence is 'images that record almost the whole brain at work.' The passage gives no poll results, so it is not 'a poll on what most people believe about the brain'; it tells no personal story, so it is not 'stories about changes in the brain of one person over time'; and it gives no history of the myth, so it is not 'an old account that traces where the brain myth began'.

Correct answer: Persistent in spite of the evidence

A myth that 'refuses to die' keeps going even though, as the passage shows, brain scans contradict it, so the phrase suggests the myth is 'persistent in spite of the evidence.' 'On its way out of the public mind' reverses the phrase. 'Supported by most of the evidence' contradicts the passage, which calls the idea 'simply false.' 'Harmful to members of the public who believe it' reads 'die' too literally; the phrase is about how long the myth lasts, not whom it hurts.

Correct answer: Supports the statement with exact figures

The text says 'most students walk to school,' and the chart's 55 percent for walking is more than half, so the chart 'supports the statement with exact figures.' 'Weakens the claim, since barely half of them walk' is wrong, because 55 percent is a majority. 'Lists the reasons that students choose to walk' misreads the chart, which gives percentages, not reasons. 'Proves the school should add more bus routes' goes beyond the data, which describe how students travel and recommend nothing.

Correct answer: A quality of newness and freshness

The app's novelty is what wore off once the excitement of something new faded, so the word names a quality of newness and freshness. 'A cheap trinket sold at a gift shop' and 'a comic act or song done for laughs' are real senses of novelty (a novelty item, a novelty act), but neither is something that wears off as users drift away; 'a long work of fiction in print' confuses novelty with the related word novel.

Correct answer: Mangroves guard coasts and give young fish safe havens.

The passage gives mangroves two roles, shielding coastlines from storm waves and sheltering young fish, and closes by saying that protecting them protects both people and the sea, so the main idea is that mangroves guard coasts and give young fish safe havens. Naming one role alone is too narrow, so it is wrong to say mangroves mainly shield the shore from wind and storms. The roots resist that damage, and the passage never says mangroves are steadily worn down by storm waves and erosion. Where mangroves grow is only the setting in the opening sentence, so it is too narrow to say mangroves are trees and shrubs that grow along salty shores.

Correct answer: Give young fish a safe place to grow

The passage says the roots 'shelter young fish, serving as nurseries for ocean life,' so they are nurseries because they give young fish a safe place to grow. The roots do shield coastlines from storm waves, but that is their other job, not the nursery role. Nothing suggests they raise new mangrove trees for the forest, which reads 'nurseries' as plant nurseries, or that they feed sea creatures across the ocean.

Correct answer: To guard against danger

The roots 'shield coastlines from storm waves and erosion,' so here the verb means to guard against danger. Shield can also mean to hide out of sight, but the roots are not hiding the coast. The noun senses, a badge carried by police and armor carried by a knight, do not fit a verb describing what the roots do.

Correct answer: The second states a likely result of the first.

Halving a factory's emissions would plausibly clean the town's air, so the second states a likely result of the first. Cleaner air is not one case of cutting emissions, so it is wrong that the second gives a specific example of the first. Better air quality fits with lower emissions, so it is wrong that the second contradicts the claim of the first. The sentences report different events, so it is wrong that the second simply restates the idea of the first.

Correct answer: To advise readers not to pour grease down drains

The passage opens by telling readers to think twice before pouring grease down the drain, explains the damage it does, and ends with what to do instead, so its purpose is to advise readers not to pour grease down drains. The clogging process only supports that advice, so the purpose is not 'to explain why grease does not wash out of pipes.' The passage is about prevention and never covers clearing a clog, which rules out 'to show how to clear clogs from home plumbing lines,' and it never says repair costs are rising, which rules out 'to detail the rising costs of home plumbing repairs.'

Correct answer: It sets hard and catches food on the pipe walls.

The passage says that as grease cools it 'hardens and clings to pipe walls, trapping food scraps until the pipe clogs,' so it sets hard and catches food on the pipe walls. The cooling happens to the grease, not the pipe, so it is wrong that it cools the pipe and makes the water inside freeze. Nothing suggests the pipe itself is damaged, so it is wrong that it eats into the pipe and leaves holes in the metal. Grease hardens instead of staying fluid, so it is wrong that it stays liquid and pools in the pipe at low bends.

Correct answer: Sticks closely to a surface

Grease 'clings to pipe walls, trapping food scraps,' so the word means sticks closely to a surface. The other choices are real senses of cling that do not fit grease on a pipe: leans on others for comfort (clinging to a person), holds fast to an old belief (clinging to an idea), and lingers like a strong odor (a smell that clings).

Correct answer: Saliva quietly performs several vital jobs for the body.

The passage lists three jobs (starting digestion, protecting teeth, carrying chemicals to the taste buds) and stresses that we rarely notice them, so the main idea is that saliva quietly performs several vital jobs for the body. Taste is only one of those jobs, so it is too narrow to say saliva matters mainly because it lets us taste our food. Digestion is also just one job, so it is too narrow to say saliva serves chiefly to break down starch in meals. The last sentence says the mouth depends on saliva more than most people realize, the reverse of the claim that saliva matters much less to the mouth than people think.

Correct answer: By rinsing bacteria off the teeth

The passage says saliva 'protects teeth by washing away bacteria,' so it protects them by rinsing bacteria off the teeth. Breaking down starches is its digestive job, so 'by breaking down starch on the teeth' misplaces that detail; the dissolved chemicals go to the taste buds, so 'by moving chemicals to the teeth' is wrong; and nothing in the passage supports 'by forming a hard shell on the teeth.'

Correct answer: The saliva in the mouth

The whole passage describes saliva, and 'this constant fluid' points back to it: it is the saliva in the mouth that works all day without being noticed. The dissolved chemicals are something saliva carries, not the fluid itself, and the passage never mentions the gastric juices or the mucus in the throat.

Correct answer: 400

Each serving has 200 calories, so two servings provide 2 x 200 = 400 calories. Stopping after one serving gives 200. The other slip treats grams as calories: two servings hold 2 x (8 + 30 + 5) = 86 g of fat, carbohydrates and protein, and adding that to the 400 gives 486, or adding it to a single serving's 200 gives 286. Grams measure weight, not energy, so they are never added to a calorie count.

Correct answer: Carbohydrates

By weight the label lists 30 g of carbohydrates against 8 g of fat and 5 g of protein, so carbohydrates are present in the largest amount. Calories measure energy, not weight, so the figure of 200 calories cannot be compared with the gram amounts.

Correct answer: A brief stretch of time

The volunteers rested in the shade for a while before going back to the task, so spell here means a brief stretch of time. The other choices are real senses of spell that do not fit a rest in the shade: a spoken magic charm, to warn of trouble ahead (as in clouds that spell rain), and to name letters in order.

Correct answer: Engineers are learning from how long Roman concrete lasts.

The passage contrasts concrete that has lasted two thousand years with modern concrete that crumbles in decades, then says engineers are studying the Roman recipe and the past may hold lessons, so the main idea is that engineers are learning from how long Roman concrete lasts. It is modern concrete that crumbles, and the passage never says that studies have found Roman concrete weaker than modern concrete. The mineral detail explains the durability but is too narrow to be the main idea: seawater reacting with Roman concrete formed rare minerals. The passage gives no reason for the use of seawater, so it does not support the claim that Roman concrete was made with seawater for lack of fresh water.

Correct answer: Minerals formed as seawater reacted with the mix

Scientists found that 'seawater reacting with the Roman mix actually strengthened it over time, forming rare minerals,' so the answer is minerals formed as seawater reacted with the mix. The new minerals were produced by that reaction, not added, so 'rare crystals the builders stirred into the mix' reverses cause and effect. The passage names seawater, not 'fresh water the builders had poured into the mix,' and it never mentions 'intense sunlight that baked and hardened the mix.'

Correct answer: Builders today have much to learn from old methods

The final sentence says 'the past may hold lessons for building a more durable future,' so the author believes builders today have much to learn from old methods. The author suggests learning from Roman concrete, not that builders today should switch back to ancient concrete. Cost is never discussed, so nothing supports the idea that the Roman recipe is too costly for large building jobs, and the final sentence says nothing about whether ancient methods were lost long before modern times.

Correct answer: A formula to produce a material

Engineers are studying 'this recipe' for concrete, so the word stands figuratively for a formula to produce a material. A list of steps for cooking a meal is the everyday kitchen sense, a note from a doctor naming a drug is the old sense of a prescription, and a sure cause of trouble or failure is the sense in 'a recipe for disaster'; none of these is what engineers study to build with.

Correct answer: Migrating birds find their way using several natural cues.

The passage explains that birds cross thousands of miles by using the sun, the stars and the Earth's magnetic field, a built-in compass, so the central idea is that migrating birds find their way using several natural cues. The magnetic field is just one cue, so it is too narrow to say migrating birds steer mainly by sensing magnetic fields. Young birds inherit the skill and refine it through experience, which does not mean migrating birds learn each route by following older birds. The passage names the sun, stars and magnetic field, not landmarks, so it does not say migrating birds need familiar landmarks to stay on course.

Correct answer: They are born with part of it and hone it with use

The passage says 'young birds inherit part of this ability and refine it through experience,' so they are born with part of it and hone it with use. Nothing mentions lessons from other birds, so 'they are taught each route by adults in their flock' is unsupported; the word 'part' rules out 'they are born with the whole skill already in place'; and the stars are a cue for steering, not a training method, so 'they are trained by gazing at stars and the moon' is wrong.

Correct answer: A sense of direction birds are born with

The 'built-in compass' is a metaphor: nature equips the birds themselves with a way to find direction, so it describes a sense of direction birds are born with. Read literally it would be a small tracking device fitted on birds, but no device is mentioned. The stars are only one cue the birds use, so 'a pattern of stars birds follow at night' is too narrow, and young birds inherit and refine the skill rather than learning 'a route that older birds teach the young.'

Correct answer: To make better with practice

Young birds 'refine it through experience,' so the word means to make better with practice. The other choices are real senses of refine that do not fit a skill being developed: to remove impurities from metal (refining ore), to make people more courteous (refined manners), and to free people from moral flaws.

Correct answer: The place shows strengths as well as flaws

Reviewer 1 praises the heaped plates and fair price while Reviewer 2 complains of a long wait, so together the reviews suggest the place shows strengths as well as flaws. The reviews describe different things and do not conflict, so nothing suggests one of the two reviews seems to be inaccurate. Neither reviewer weighs one point against the other, so the reviews do not say the large portions make up for the slow service, and a single complaint does not show the restaurant is known mostly for slow service.

Correct answer: Be troubled by Reviewer 2's report of long waits

A diner who cares more about speed than portion size would be troubled by Reviewer 2's report of long waits, since that review describes nearly an hour between ordering and eating. Reviewer 1 praised the amount of food, which this diner values less, so the diner would not choose the restaurant for Reviewer 1's big portions, and that praise says nothing about speed, so the diner has no reason to expect fast service based on Reviewer 1's praise. Speed is what this diner cares about, so the diner would not wave off Reviewer 2's complaint as a trivial matter.

Correct answer: Strict and inflexible

A coach who refuses to make exceptions even for star players is being strict and inflexible about the curfew. Firm can also mean solid and compact, as a verb it can mean to make solid or tight (to firm up), and as a noun it names a business partnership, but none of these describes how the coach treats the rule.

Correct answer: The tongue is built for endurance instead of raw power.

The passage calls the strongest-muscle label misleading and ends by saying the tongue's true strength 'lies in endurance, not power,' so the main idea is that the tongue is built for endurance instead of raw power. The passage sets out to correct the popular claim that the tongue is the strongest muscle in the body by force. Speaking and swallowing are only examples of its work, so it is too narrow to say the tongue muscle mainly helps people speak and swallow. The passage calls the tongue tireless, so it is wrong that the tongue tires out faster than the muscles of the jaw.

Correct answer: Show the jaw presses harder than the tongue

The passage says that 'by raw force, larger muscles like those in the jaw exert more pressure,' so the author mentions the jaw to show the jaw presses harder than the tongue, which is why the strongest-muscle label is misleading. The example works against any attempt to prove the tongue is far stronger than the jaw. It compares force, not stamina, so it is not there to show how the jaw tires out before the tongue does, and nothing in the passage is meant to suggest the tongue keeps the jaw from wearing out.

Correct answer: Creating false impressions

The passage calls the strongest-muscle claim 'misleading' because it sounds true but leaves out that larger muscles exert more force, so the word means creating false impressions. The claim is not hard for people to understand, and the passage is correcting it, not saying it is backed by careful research; leading a hiker the wrong way is the literal, physical sense of mislead, which does not fit a statement.

Correct answer: Glaciers slowly creep and carve terrain over long periods.

The passage describes glaciers as rivers of ice that move inches or feet a day and, over thousands of years, carve valleys and lakes, so the main idea is that glaciers slowly creep and carve terrain over long periods. Grinding rock is one detail of that work, so it is too narrow to say glaciers grind rock to fine dust as they slide down slopes. The passage says glaciers only seem permanent, so it is wrong that glaciers stay frozen and still for many thousands of years. 'Rivers of ice' is a comparison, so it does not mean glaciers are rivers that carry liquid water down valleys.

Correct answer: Flow along at an extremely slow pace

Calling glaciers 'rivers of ice in slow motion' compares them to flowing water while stressing their slowness, so the image shows that glaciers flow along at an extremely slow pace. The phrase does not say they move as quickly as rivers of water; it is a comparison, not a claim that they melt into rivers in warm weather; and likening them to rivers rules out the idea that they stay frozen in one place for many years.

Correct answer: The slow creep of glaciers through the ages

The passage says that over thousands of years glaciers 'have carved valleys and lakes across the land,' so those features were formed by the slow creep of glaciers through the ages. 'Rivers of ice' is only a comparison, so nothing points to water in rivers flowing through the region; gravity pulls the glaciers themselves downhill, not loose rock that gravity pulls down the slopes; and the dust is what glaciers grind from rock, not fine dust that winds swept across the regions.

Correct answer: Crushing into a powder

Glaciers are 'grinding rock into fine dust,' so the word means crushing into a powder. The other choices are real senses of grind that do not fit rock being turned to dust: scraping with a harsh noise (gears grinding), sharpening a knife on stone, and toiling at a task for hours (the daily grind).

Correct answer: Cursive is worth keeping for the benefits it offers

The author grants that cursive is fading, then lists its benefits (memory, fine motor skills, reading historical documents) and warns that dropping it may cost more than it saves, so the argument is that cursive is worth keeping for the benefits it offers. 'Good riddance' is the view the author argues against, so it is not the author's claim that cursive is outdated and schools are right to drop it. Old documents are only one of several reasons, so it is too narrow to say cursive matters chiefly as a way to read old documents, and the author never says cursive should be taught in place of typing in schools.

Correct answer: It aids recall and fine motor skills and helps us read old papers.

The author says forming connected letters by hand aids 'memory and fine motor skills' and that reading historical documents 'also requires the skill,' so the reason given is that it aids recall and fine motor skills and helps us read old papers. The passage never compares speed, so it does not claim it is faster than typing and helps pupils take class notes by hand. Spelling and neatness are never mentioned, so it does not say it improves spelling and keeps connected letters neat and uniform. Appearance and warmth are never discussed either, so it does not argue it looks good and makes cards and letters feel more personal.

Correct answer: A change to be welcomed

'Good riddance' is said of something people are glad to be free of, so those speakers see the loss of cursive as a change to be welcomed. They are not mourning a deep and painful loss. Calling the change a costly school mistake or a threat to be opposed reflects the author's own view, which argues against those speakers.

Correct answer: To toughen by heating and cooling

The blacksmith heats and cools the blade 'to make it both hard and flexible,' so temper means to toughen by heating and cooling. Temper can also mean to tone down or make less intense, and as a noun it can mean a habit of becoming angry quickly or a calm, steady state of mind, but none of these fits what a blacksmith does to steel.

Correct answer: Trees in a forest work together through underground links.

The passage describes fungal threads that join tree roots into a network sharing water, nutrients and signals, and ends by calling the forest a connected community, so the main idea is that trees in a forest work together through underground links. The passage shows the trees sharing resources, so it does not support the claim that trees in a forest compete fiercely for water and minerals. The signals travel through the underground network, and the passage never says trees in a forest send warning signals to neighbors by air. A large tree feeding smaller ones is one example, so it is too narrow to say trees in a forest depend on the big old trees to feed them.

Correct answer: Nutrients, water, and warning signals

The passage says the fungal network 'shares water, nutrients, and even warning signals,' so what flows through it is nutrients, water, and warning signals. Fungal threads, tree roots, and soil are what the network is made of and where it lies, not what travels through it. The passage never mentions sunlight, rainstorms, and morning dew, nor sticky sap, pollen, and alarm sounds.

Correct answer: Stress that the trees work together as a community

By saying the forest behaves 'less like a crowd of individuals than a connected community,' the final sentence works to stress that the trees work together as a community. The contrast rejects the crowd picture, so it does not prove that the trees compete like strangers in a crowd. Older trees feeding smaller ones is an example from earlier in the passage, so the sentence does not mainly point out that old trees feed the young ones nearby, and logging is never mentioned, so it does not warn that cutting down trees can harm the whole forest.

Correct answer: A system of linked parts

Threads of fungus connect the roots of many trees into one linked whole, so network here means a system of linked parts. A chain of radio stations, a circle of work contacts, and a mesh of knotted cords are real senses of network, but none describes fungal threads joining tree roots underground.

Correct answer: Reading fiction may help adults become more empathetic.

The passage reports that adults who read fiction regularly tend to show greater empathy, perhaps because stories let readers inhabit other minds, so its main idea is 'Reading fiction may help adults become more empathetic.' The option 'Adults who read fiction may already be more empathetic.' reverses the cause, while the passage presents fiction as the practice that builds empathy; 'Fiction may help children far more than it helps their parents.' adds a comparison the passage never makes, since it says the benefit extends beyond children; and 'Fiction may help adults cope with their own painful feelings.' misses the point, because the passage stresses understanding feelings unlike our own.

Correct answer: Builds understanding of feelings through steady practice

A gym is where muscles grow stronger through repeated exercise, so calling fiction 'a gym for the heart' means it builds emotional understanding through practice, which matches the passage's point that we practice understanding feelings unlike our own. The heart is figurative here, so the metaphor is not about physical health; it describes strengthening rather than wearing emotions down; and it concerns understanding others, not expressing one's own feelings.

Correct answer: Help readers understand how someone else feels

The author ties regular fiction reading to greater empathy and says that following a character's struggles lets us practice understanding feelings unlike our own, so the author values fiction for helping readers understand how someone else feels. Bedtime stories are only the passage's starting point, and it says nothing about escaping worries or learning historical facts.

Correct answer: To enter and occupy

Here 'inhabit' is figurative: stories let readers enter and occupy other minds by imagining a character's thoughts. 'To live in as a home' is the word's literal sense for a place, which does not fit minds; 'to hold back or restrain' is the meaning of the look-alike word 'inhibit'; and 'to receive from parents' belongs to 'inherit.'

Correct answer: Although

'Although' signals concession: it grants that the evidence was strong while introducing the contrasting fact that the jury still hesitated. 'Because' would make the strong evidence the reason for hesitating, 'otherwise' points to an alternative and cannot join the two clauses by itself, and 'unless' sets up a condition; none of them expresses the contrast the sentence needs.

Correct answer: Bamboo is a grass valued as a renewable material for its rapid growth.

Every sentence builds toward one point: bamboo, though technically a grass, grows so fast and regrows so quickly that it is prized as a renewable material. The passage calls bamboo a grass rather than a tree, the meter-a-day growth is a supporting detail about some species, and the passage never predicts that bamboo will replace wood.

Correct answer: It grows back fast once it has been harvested.

The passage says bamboo is prized as a renewable material 'because it regrows so quickly after cutting,' so the reason is that it grows back fast once harvested. Its height and its classification as a grass are separate facts, and its strength is mentioned as a building quality, not as the reason it is renewable; the passage never compares it with wood.

Correct answer: Highlight how surprisingly tall bamboo can grow

Calling bamboo 'technically a grass' and then noting that it grows taller than many trees creates a surprising contrast, so the detail is there to 'highlight how surprisingly tall bamboo can grow'. The classification is not used to 'explain how bamboo can regrow so quickly after cutting' (regrowth is a separate point about renewability), the passage never sets out to 'suggest that scientists have classified bamboo wrongly', and it does not 'show that bamboo is weaker than most real trees', since it praises bamboo's strength.

Correct answer: Held in high regard

Bamboo is 'prized' as a renewable material, meaning people hold it in high regard for that use. 'Forced open by prying' is a different sense of the verb (to prize a lid off), 'won in a contest' confuses the word with the noun 'prize,' and 'marked with a price' confuses it with 'priced.'

Correct answer: A study showing night crashes dropped in similar towns after lights were added

The argument claims that more lighting will reduce nighttime accidents, so the strongest support is 'a study showing night crashes dropped in similar towns after lights were added', which shows the claimed effect in comparable towns. 'A survey showing that most residents would welcome brighter lights near their homes' shows popularity rather than effectiveness, 'a report on the yearly cost of powering the new streetlights' bears on the budget rather than on safety, and 'the opinion of a driver who feels the roads are unsafe after dark' shows that a problem may exist without showing that lights would solve it.

Correct answer: Is there proof that more lights would mean fewer crashes?

The argument rests on the claim that better lighting reduces nighttime accidents, so the question that best tests it is 'Is there proof that more lights would mean fewer crashes?' The other questions also ask for proof, but of things that say nothing about whether the claimed effect is real: 'Is there proof that local companies would supply new lights?' concerns the supplier, 'Is there proof that most residents would like more lights?' measures popularity, and 'Is there proof that the writer lives where new lights would go?' concerns the writer's personal stake.

Correct answer: Present in large amounts

Detail that paints each scene so vividly that readers feel they could step inside is plentiful detail, so 'rich' here means present in large amounts. 'Owning great wealth' is the sense used for people, 'made with lots of butter' describes rich food, and 'good for growing crops' describes rich soil; none fits the detail in a novel.

Correct answer: Goldfish recall much more than people tend to think.

The passage calls the few-seconds memory a myth and cites experiments showing that goldfish learn tasks and remember them for months, so its main idea is 'Goldfish recall much more than people tend to think.' The option 'Goldfish learn from experience to push levers.' is one supporting example, too narrow to be the main idea; 'Goldfish keep memories for no more than a few seconds.' is the myth the passage rejects; and 'Goldfish rely on instinct instead of learning from experience.' contradicts the passage's evidence of learning.

Correct answer: Studies in which goldfish recalled tasks months later

The author challenges the myth with experimental evidence: goldfish have learned to push levers and recognize owners and can remember tasks for months. The popular belief about a few seconds is the claim being challenged, not evidence against it, and the passage offers no personal anecdote and quotes no scientist.

Correct answer: Modest but underrated

Calling the goldfish 'humble' presents it as an ordinary, unassuming creature, and the words that follow, 'far smarter than its reputation suggests,' show that it is underrated, so the author regards it as 'modest but underrated'. 'Shy around its owners' reads humble as bashful, which the passage never suggests; 'obedient but slow-witted' reads humble as lowly, but the passage calls the goldfish far smarter than its reputation; and 'proud of its cleverness' is the opposite of humble.

Correct answer: General opinion about it

A reputation is what people generally think about someone or something, so a goldfish 'far smarter than its reputation suggests' is smarter than the general opinion about it. 'Wide public fame' is a different sense (being well known), 'repeating an action' confuses the word with 'repetition,' and outward appearance is not what a reputation describes.

Correct answer: Creating less waste is wiser than recycling it later.

The passage opens by saying that recycling helps but reducing waste in the first place matters more, and the rest supports that claim, so the central idea is 'Creating less waste is wiser than recycling it later.' The option 'Recycling is the best way to make less waste.' reverses the passage's ranking of recycling below reducing; 'Collecting and sorting materials for recycling takes energy.' is one supporting detail, too narrow to be the central idea; and 'Recycling does more harm than good and should be dropped.' contradicts the passage, which calls recycling helpful.

Correct answer: Reducing waste should be our highest priority

Saying the slogan lists 'reduce' first 'for a reason' implies the order reflects importance, so reducing waste should be our highest priority. The passage ranks recycling below reducing, the phrase 'for a reason' rules out a random order, and the author points to importance rather than to how easy the slogan is to remember.

Correct answer: Uses energy yet leaves certain materials unrecycled

The passage names two drawbacks: recycling still uses energy to collect, sort, and process materials, and not everything can be recycled. It says nothing about recycling costing more than new products, creating extra waste during sorting, or encouraging people to buy more.

Correct answer: A point where something begins

Cutting waste 'at the source' means stopping it where it begins, before it is ever created. A spring that feeds a river and a person who gives news tips are other senses of the word, and a reference book is a source of information; none fits waste that is cut before it exists.

Correct answer: To persuade office workers to put greenery on their desks

The passage opens with a direct instruction, 'Keep a houseplant or two on your desk,' and then lists benefits to make the case, so its purpose is to persuade readers to put a plant on their desks. The studies, the air filtering, and the dull offices are supporting points, not the purpose.

Correct answer: They can calm workers and help them stay focused.

The passage says studies suggest indoor plants can lower stress and sharpen focus during long work hours, so the benefit it names is 'They can calm workers and help them stay focused.' The option 'They can clear most pollutants and odors from office air.' overstates the passage, which says plants may filter the air only slightly; 'They can make the long work hours feel shorter.' is never claimed; and 'They can help brighten dim offices by reflecting the sun.' takes the 'brighter' workday literally, when the passage means it figuratively.

Correct answer: A potted plant on the desk

The passage is about keeping a houseplant on your desk, so 'a small green companion' is that plant, described as if it were a friend. 'Green' here is the color of leaves, not inexperience or an environmental habit, and the passage mentions no pet.

Correct answer: Brings real gains but also carries costs

Passage 1 shows a learning benefit and Passage 2 shows costs in stress and family time, so a reader weighing both should conclude that homework 'brings real gains but also carries costs'. Saying that it 'brings some stress but also gains worth the cost' adds a verdict that the gains outweigh the stress, which takes only Passage 1's side; saying that it 'should give way to more family time on school nights' or 'should stay limited to weekends to protect children' takes only Passage 2's side.

Correct answer: Give short assignments aimed at key skills

Passage 1 values practice at home, and Passage 2 objects to long nightly assignments that cause stress and crowd out family time; short assignments aimed at key skills keep the practice while limiting the load. Giving up homework sacrifices the learning benefit, while big weekend projects and a doubled nightly load add to the stress and the lost family time.

Correct answer: Takes away unfairly

Homework that is 'stealing hours' a family might spend together is unfairly taking that time away from them. 'Slips by without notice' is the sense in 'steal away,' 'draws the most attention' is the sense in 'steal the show,' and 'advances to another base' is the baseball sense; none describes what homework does to family time.

Correct answer: Flame color signals how hot the fire burns.

The passage opens by saying that a flame's color reveals its temperature and then supports the claim with the candle and gas-stove examples, so its main idea is 'Flame color signals how hot the fire burns.' The option 'Yellow flames burn hotter than blue ones.' reverses the passage, which says yellow flames are the cooler ones; 'Engineers need thermometers to judge heat.' contradicts the point that experts read the colors without a thermometer; and 'Colors in nature carry secret messages about heat.' stretches the passage's 'secret language' metaphor, which applies to fire, to colors throughout nature.

Correct answer: The blue flame of a gas stove

The passage states that a candle's yellow flame is cooler 'while the blue flame of a gas stove burns hotter,' so the gas stove's blue flame is the hotter one. The candle's yellow flame is the cooler one, and the passage links heat to color, not to a flame's size or brightness.

Correct answer: Gives trained eyes clues about how hot the fire is

A secret language is one that only people who know it can read, and the passage says engineers and chemists read flame colors to gauge heat, so the phrase means flame color gives trained eyes clues about a fire's heat. The experts who read it show that it is not hidden from scientists or impossible to measure, and nothing in the passage says ancient people used it to send messages.

Correct answer: To measure or estimate

Engineers and chemists read flame colors 'to gauge heat without a thermometer,' that is, to measure or estimate how much heat is present. Scooping out a hollow and charging a buyer too much are meanings of the look-alike word 'gouge,' and turning something up or down is what a control knob does, not what gauging means.

Correct answer: Honey lasts for ages because it barely lets bacteria grow.

The passage claims that honey never truly spoils and explains why: its low moisture and natural acidity make it nearly impossible for bacteria to grow, so its main idea is 'Honey lasts for ages because it barely lets bacteria grow.' The option 'Ancient tombs held honey that archaeologists later dug up.' is supporting evidence, too narrow to be the main idea; 'Ancient people put honey in tombs because the dead needed food.' gives a reason the passage never states; and 'Bacteria multiply quickly inside honey after a jar is opened.' contradicts the passage, which says bacteria can hardly grow in honey at all.

Correct answer: It is low in moisture and naturally acidic

The passage says honey's 'low moisture and natural acidity make it nearly impossible for bacteria to grow,' so bacteria fail because honey is low in moisture and naturally acidic. Sealed pots and tombs describe where honey has been kept, not why bacteria cannot grow in it, and the passage never mentions chilling, sunlight, salt, or burial.

Correct answer: Give vivid proof of how long honey stays edible

Honey from ancient tombs that is still edible after thousands of years is striking evidence for the opening claim that honey never truly spoils. The passage does not explain how ancient people stored honey, describe burial customs, or compare honey's value with gold.

Correct answer: Needing quick attention

A 'pressing deadline' is one that needs quick attention, which is why the team worked through the night. Smoothing cloth with an iron, pushing down on a button, and squeezing juice from fruit are physical senses of 'press' that do not describe a deadline.

Correct answer: Hummingbirds burn fuel so fast they feed nonstop and conserve it overnight.

Each detail serves one idea: the hummingbird's racing heart demands so much energy that it must eat almost constantly by day and slow its body at night to save energy, so the central idea is 'Hummingbirds burn fuel so fast they feed nonstop and conserve it overnight.' The option 'Hummingbirds have hearts that can beat over a thousand times a minute in flight.' is a supporting detail, too narrow to be the central idea; 'Hummingbirds tire so quickly in flight that they sleep deeply at night.' gives the wrong reason, since the passage says the nighttime state saves energy rather than relieving tiredness; and 'Hummingbirds help flowers by carrying pollen over great distances.' is never mentioned.

Correct answer: By slowing its body into deep rest

The passage says that at night the hummingbird 'slows its body into a deep, sleep-like state to save energy.' Speeding up its heart would use more energy, and the passage mentions no extra meal before dark and no nighttime flower visits.

Correct answer: A constant scramble to find enough food

A race against starvation is a constant, urgent effort to eat before running out of energy, which matches the passage's point that the bird must eat almost constantly. The race is figurative, not a contest with other birds; it describes staying ahead of starvation rather than sliding toward it; and nothing about the bird's life is calm.

Correct answer: Extremely rapid

A heart beating over a thousand times a minute sets a 'furious pace,' meaning an extremely rapid, intense one. 'Filled with rage' is the word's sense when it describes a person's anger, while 'done in secret' and 'full of curiosity' belong to the look-alike words 'furtive' and 'curious.'

Correct answer: 10

Multiply before adding or subtracting: 4 x 2 = 8, then 3 + 8 - 1 = 10. Working left to right gives (3 + 4) x 2 - 1 = 13, adding the 1 instead of subtracting it gives 3 + 8 + 1 = 12, and making both slips gives 15.

Correct answer: 5/8

0.625 is 625 thousandths, or 625/1000; dividing the numerator and denominator by 125 gives 5/8. 25/4 treats 0.625 as 625 hundredths, 625/100, and equals 6.25. 3/4 equals 0.75 and 2/3 is about 0.667; both are close to 0.625, but neither equals it.

Correct answer: $30

25% of $40 is $10, so the sale price is $40 - $10 = $30. Stopping at $10 gives the discount, not the price; $39 treats 25% as 0.025 and takes off only $1; taking 25% of the sale price instead of the original price, $40 ÷ 1.25, gives $32.

Correct answer: 17/12

Rename both fractions in twelfths: 3/4 = 9/12 and 2/3 = 8/12, so the sum is 9/12 + 8/12 = 17/12. Renaming only 3/4 gives 9/12 + 2/12 = 11/12; multiplying the numerators but adding the denominators gives (3 × 2)/(4 + 3) = 6/7; adding the numerators and the denominators gives (3 + 2)/(4 + 3) = 5/7.

Correct answer: 8

Sugar goes from 3 cups to 12 cups, a factor of 4, so flour goes from 2 cups to 2 × 4 = 8 cups. Adding the factor instead of multiplying by it gives 2 + 4 = 6; adding instead of scaling (sugar rose by 9 cups, so flour 2 + 9) gives 11; multiplying 12 by 2 and ignoring the 3 gives 24.

Correct answer: 12

15% of 80 is 0.15 × 80 = 12. Taking 15% off 80 gives 80 - 12 = 68; adding 15% to 80 gives 80 + 12 = 92; writing 15% as 1.5 instead of 0.15 gives 1.5 × 80 = 120.

Correct answer: 0.7

Compare place by place: 0.7 = 0.700, which is greater than 0.699 and 0.659, and every negative number is less than a positive one. 0.699 and 0.659 only look larger because they have more digits and 699 and 659 are bigger whole numbers than 7; -0.9 is below zero even though 9 tenths is more than 7 tenths.

Correct answer: 12

24 = 2^3 × 3 and 36 = 2^2 × 3^2, so the shared factors are 2^2 × 3 = 12. 72 is the least common multiple, not the greatest common factor; 36 takes the larger power of 3 (2^2 × 3^2) and does not divide 24; 9 is 3^2, a factor of 36 but not of 24.

Correct answer: 24

8 = 2^3 and 6 = 2 × 3, so the least common multiple is 2^3 × 3 = 24, the first multiple of 8 that 6 divides. 2 is the greatest common factor, not the least common multiple; 8 is just the larger number, 2^3 without the factor 3, so 6 does not divide it; 48 = 6 × 8 is a common multiple but not the least one.

Correct answer: 50

Average speed is distance ÷ time = 150 ÷ 3 = 50 miles per hour. Multiplying 150 by 3 gives 450; dividing 15 instead of 150 by 3 gives 5; 45 is too slow, since 45 × 3 = 135 miles, not 150.

Correct answer: 0

-8 + 5 = -3, and subtracting -3 means adding 3, so -3 + 3 = 0. Treating - (-3) as -3 gives -3 - 3 = -6; ignoring every sign gives 8 + 5 + 3 = 16; dropping the sign of -8 and also treating - (-3) as -3 gives 8 + 5 - 3 = 10.

Correct answer: 29

29 has no factors other than 1 and itself, so it is prime. 39 = 3 × 13, 51 = 3 × 17 and 57 = 3 × 19, so each of them is composite even though none is even or ends in 5.

Correct answer: 40%

2/5 = 2 ÷ 5 = 0.40, and 0.40 = 40%. Moving the decimal point only one place gives 4%; dividing 5 by 2 instead gives 2.5 = 250%; dividing 5 by 2 and also moving the decimal point only one place gives 25%.

Correct answer: 672

672 is 6 hundreds and 72; since 72 is 50 or more, 672 rounds up to 700. 649 rounds to 600 (rounding to 650 first and then to 700 is double rounding); 753 rounds up to 800, because its tens digit is 5 (rounding down by looking at the ones digit 3 is the slip); 786 rounds to 800 (dropping the tens and ones to get 700 is truncating, not rounding).

Correct answer: 16

5^2 = 25 and 3^2 = 9, so 25 - 9 = 16. Doubling 3 instead of squaring it gives 25 - 6 = 19; adding the squares instead of subtracting them gives 25 + 9 = 34; doubling both, or squaring the difference (5 - 3)^2, gives 4.

Correct answer: $5.00

8 pencils cost $2.00, so one pencil costs $0.25 and 20 pencils cost 20 × $0.25 = $5.00. Treating $2.00 as the price of one pencil gives 20 × $2.00 = $40.00; treating the 12 extra pencils as 12 extra dollars gives $2.00 + $12.00 = $14.00; inverting the rate (4 pencils per dollar used as $4 per pencil) gives $80.00.

Correct answer: 12

Absolute value is distance from zero, which is never negative, so |-12| = 12. -12 keeps the sign instead of removing it; 1/12 is the reciprocal of 12 and -1/12 is the reciprocal of -12, and neither is the distance from zero.

Correct answer: 3500

1 kilometer = 1000 meters, so 3.5 × 1000 = 3500 meters. Using 100 meters per kilometer gives 350; reading 3.5 km as 3 km and 5 m gives 3005; reading it as 3 km and 50 m gives 3050.

Correct answer: 3/8

Rename 1/2 as 4/8; then 7/8 - 4/8 = 3/8. Subtracting the numerators and the denominators separately gives (7 - 1)/(8 - 2) = 6/6; multiplying instead gives 7/8 × 1/2 = 7/16; dividing instead gives 7/8 × 2 = 14/8 = 7/4.

Correct answer: $48

A 20% increase takes $50 to $60, and a 20% decrease of $60 removes $12, leaving $48. Assuming the two changes cancel gives $50; stopping after the increase gives $60; taking the $12 decrease off the original $50 gives $38.

Correct answer: 6000

10^3 = 1000, so 6 × 10^3 = 6 × 1000 = 6000. Multiplying 6 by the exponent gives 18; reading 10^3 as 10 × 3 gives 6 × 30 = 180; applying the exponent to the whole product, (6 × 10)^3, gives 216,000.

Correct answer: 7/3

The reciprocal of a/b is b/a, so the reciprocal of 3/7 is 7/3 (check: 3/7 × 7/3 = 1). -3/7 is the opposite of 3/7, not its reciprocal; 3/7 leaves the number unchanged, and 3/7 × 3/7 = 9/49, not 1; -7/3 is the negative reciprocal, and 3/7 × (-7/3) = -1, not 1.

Correct answer: 0.02

4 × 5 = 20, and the two factors have 1 + 2 = 3 decimal places in all, so 0.4 × 0.05 = 0.020 = 0.02. Adding instead gives 0.4 + 0.05 = 0.45; subtracting instead gives 0.4 - 0.05 = 0.35; counting four decimal places gives 0.0020 = 0.002.

Correct answer: 75%

18 ÷ 24 = 0.75, which is 75%. 25% is the share of games lost (6 of 24); subtracting the 6 losses from 100 gives 94%; multiplying 18 by 4 as if 24 × 4 were 100, not 96, gives 72%.

Correct answer: -8

(-2)^3 = (-2) × (-2) × (-2) = 4 × (-2) = -8; an odd power of a negative number is negative. Multiplying -2 by the exponent 3 gives -6; multiplying 2 by the exponent 3 and also dropping the sign gives 6; dropping the sign gives 8, but a product of three negative factors is negative.

Correct answer: 12

The girls are 3/5 × 30 = 18, so the boys are 30 - 18 = 12 (equivalently 2/5 × 30 = 12). 18 is the number of girls, not boys; 20 takes 2/3 of the class instead of 2/5; 10 takes 1/3 of the class instead of 2/5.

Correct answer: 12

sqrt(144) = 12 because 12 × 12 = 144. Halving 144 gives 72; writing 144 as 16 × 9 and taking the square root of only the 9 gives 16 × 3 = 48; squaring 144 instead of taking its root gives 20,736.

Correct answer: 3/8, 0.4, 1/2

As decimals, 3/8 = 0.375, 0.4 = 0.400 and 1/2 = 0.5, so from least to greatest the order is 3/8, 0.4, 1/2. The list 1/2, 0.4, 3/8 runs from greatest to least; 1/2, 3/8, 0.4 orders the numbers by their first digits 1, 3 and 4; 0.4, 3/8, 1/2 wrongly ranks 3/8 above 0.4, but 3/8 = 0.375.

Correct answer: $22.50

Time-and-a-half is 1.5 times the regular rate: 1.5 × $15 = $22.50. Doubling the rate gives $30.00, which is double time; adding 1.5 to the rate instead of multiplying by it gives $15 + $1.50 = $16.50; dividing $15 by 1.5 gives $10.00.

Correct answer: 1/12

In this question 'of' means multiply: 1/3 × 1/4 = 1/12. Adding the numerators and the denominators gives (1 + 1)/(3 + 4) = 2/7; adding the numerators but multiplying the denominators gives (1 + 1)/(3 × 4) = 2/12; adding the denominators instead of multiplying them gives 1/(3 + 4) = 1/7.

Correct answer: 2:3

Divide both terms by their greatest common factor, 6: 12 ÷ 6 = 2 and 18 ÷ 6 = 3, giving 2:3. 3:2 reverses the order of the terms; 2:5 compares 12 with the total 12 + 18 = 30; 3:5 compares 18 with that total, 18:30.

Correct answer: $270

The tax is 0.08 × $250 = $20, so the total cost is $250 + $20 = $270. $20 is the tax alone; reading 8% as $8 gives $250 + $8 = $258; using 0.008 instead of 0.08 adds only $2, giving $252.

Correct answer: 2 2/3

Regroup 5 as 4 3/3; then 4 3/3 - 2 1/3 = 2 2/3. Subtracting the whole numbers and bringing down the 1/3 gives 3 1/3; borrowing 1 for the fraction without reducing 5 to 4 gives 3 2/3; reducing 5 to 4 without turning the borrowed 1 into 3/3, and then bringing down the 1/3, gives 2 1/3.

Correct answer: 150

Each hour has 60 minutes, so 2.5 × 60 = 150 minutes. Ignoring the half hour gives 2 × 60 = 120; reading 2.5 hours as 2 hours 5 minutes gives 125; dividing 60 by 2.5 gives 24.

Correct answer: 400

Dividing by 0.25 is the same as multiplying by 4, so 100 ÷ 0.25 = 400. Multiplying by 0.25 instead gives 25; misplacing the decimal point as 2.5 gives 100 ÷ 2.5 = 40; making both slips, multiplying and misplacing the decimal point, gives 100 × 2.5 = 250.

Correct answer: 175

Each inch stands for 50 miles, so 3.5 × 50 = 175 miles. Ignoring the half inch gives 3 × 50 = 150; reading 3.5 as 3 inches plus 5 miles gives 150 + 5 = 155; dividing 50 by 0.5 for the half inch gives 150 + 100 = 250.

Correct answer: 2^6

When powers with the same base are multiplied, keep the base and add the exponents: 2^4 × 2^2 = 2^(4+2) = 2^6. Multiplying the bases gives 4^6; multiplying both the bases and the exponents gives 4^8; multiplying the exponents, as for a power of a power, gives 2^8.

Correct answer: 1000

Round 49 to 50 and 21 to 20; then 50 × 20 = 1000. Rounding 21 up to 30 gives 50 × 30 = 1500; rounding only 21 gives 49 × 20 = 980; rounding only 49 gives 50 × 21 = 1050.

Correct answer: 3/4

An hour has 60 minutes, so 45/60 = 3/4. Treating an hour as 100 minutes gives 45/100 = 9/20; rounding 45 minutes up to 50 first gives 50/60 = 5/6; comparing the 15 minutes left in the hour with the 45 gives 15/45 = 1/3.

Correct answer: 25%

The increase is 250 - 200 = 50, and 50 ÷ 200 = 0.25 = 25%. Dividing the increase by the new value, 50 ÷ 250, gives 20%; dividing 200 by 250 gives 80%; dividing 250 by 200 gives 125%, the new population as a percent of the old one.

Correct answer: 0.45

1/3 is about 0.333 and 1/2 = 0.5, and 0.45 lies between them. Rounding 1/3 down to 0.3 makes 0.31 look large enough, but it is below 0.333; reading 1/3 and 1/2 as 0.3 and 0.2 leads to 0.23; 0.53 is greater than 0.50, so it lies above 1/2.

Correct answer: 5

Subtract 7 from both sides to get 3x = 15, then divide both sides by 3 to get x = 5. 15 is the value of 3x, not of x; subtracting 3 instead of dividing by it gives 12; reading 3x + 7 as if the 3 multiplied the 7 and subtracting 21 from 22 gives 1.

Correct answer: 9

9 is correct: distributing gives 2x - 8 = 10, so 2x = 18 and x = 9. 1 subtracts 8 from 10 instead of adding it, which leaves 2x = 2. 7 multiplies only the x by 2, writing 2x - 4 = 10. 24 multiplies 10 by 2 instead of dividing, giving x - 4 = 20.

Correct answer: 17

17 is correct: y = 4(5) - 3 = 20 - 3 = 17. 8 subtracts before multiplying, as if y = 4(5 - 3). 42 reads 4x as the two-digit number 45 and then subtracts 3. 6 adds 4 and 5 instead of multiplying them, then subtracts 3.

Correct answer: 3

3 is correct: slope = (8 - 2)/(3 - 1) = 6/2 = 3. -3 subtracts the y-values in one order and the x-values in the other, giving (8 - 2)/(1 - 3). 1/3 puts the run over the rise, (3 - 1)/(8 - 2) = 2/6. -1/3 makes both of those slips, (3 - 1)/(2 - 8) = 2/(-6), which gives the negative reciprocal, the slope of a line perpendicular to this one.

Correct answer: 5x + 1

5x + 1 is correct: 3x + 2x = 5x, and -4 + 5 = 1. 6x^2 + 1 multiplies 3x by 2x instead of adding the like terms. 5x - 9 treats -4 + 5 as -(4 + 5). 6x^2 - 9 makes both of those slips.

Correct answer: 36

36 is correct: multiplying both sides by 4 gives x = 4 times 9 = 36. 5 subtracts 4 from 9, which would undo an addition, not a division. 9 multiplies only the left side by 4 and leaves the right side unchanged. 2.25 divides 9 by 4 instead of multiplying by 4.

Correct answer: 36

36 is correct: square 3 first to get 9, then multiply by 4. 24 doubles 3 instead of squaring it, computing 4 times 6. 144 squares the whole product, computing (4 times 3)^2 = 12^2. 12 ignores the exponent and computes 4 times 3.

Correct answer: x > 4

x > 4 is correct: subtract 3 to get 2x > 8, then divide both sides by 2. x < 4 reverses the inequality sign, which is needed only when multiplying or dividing by a negative number. x > 6 subtracts 2 from 8 instead of dividing by 2. x < 6 makes both of those slips.

Correct answer: 2n - 5

2n - 5 is correct: twice the number is 2n, and 5 less than that subtracts 5 from 2n. 5 - 2n reverses the order and subtracts twice the number from 5. n^2 - 5 squares the number instead of doubling it. 5 - n^2 makes both of those slips.

Correct answer: (x - 3)(x + 3)

(x - 3)(x + 3) is correct: x^2 - 9 is a difference of squares, x^2 - 3^2, so it factors into a sum times a difference. (x - 9)(x + 9) uses 9 instead of its square root and multiplies out to x^2 - 81. (x - 3)(x - 3) gives both factors the same sign and multiplies out to x^2 - 6x + 9. (x - 9)(x - 9) makes both of those slips.

Correct answer: 5

5 is correct: subtracting 3x from both sides gives 2x - 2 = 8, so 2x = 10 and x = 5. 8 subtracts 2 from 10 instead of dividing by 2. 1.25 adds 3x to the left side instead of subtracting it, giving 8x = 10. 0.75 adds 3x and also subtracts 2 from 8 instead of adding it, giving 8x = 6.

Correct answer: -7

-7 is correct: in y = mx + b the constant b is the y-intercept, the value of y when x = 0, and here b = -7. 3.5 is the x-intercept, found by setting y = 0 and solving 2x - 7 = 0. 2 is the slope m, the coefficient of x, not the constant term. 7 drops the negative sign on the constant term.

Correct answer: 10

10 is correct: (-3)^2 = 9, and 9 + 1 = 10. -5 doubles -3 instead of squaring it. 4 adds 1 before squaring, computing (-3 + 1)^2. -8 treats (-3)^2 as -9, computing -9 + 1.

Correct answer: 6x^5

6x^5 is correct: multiply the coefficients (2 times 3 = 6) and add the exponents (3 + 2 = 5). 6x^6 multiplies the exponents instead of adding them. 5x^5 adds the coefficients instead of multiplying them. 5x^6 makes both of those slips.

Correct answer: C = 2m + 3

C = 2m + 3 is correct: $2 for each of m miles is 2m, plus the flat $3 fee. C = 3m + 2 swaps the flat fee and the per-mile rate. C = m/2 + 3 divides the miles by 2 instead of multiplying, reading 'per mile' as division. C = m/3 + 2 swaps the fee and the rate and also divides.

Correct answer: 3

3 is correct: distributing gives 4x + 8 = 2x + 14, so 2x = 6 and x = 3. 6 multiplies only the x by 4, writing 4x + 2 = 2x + 14, so 2x = 12. 1 adds 2x to the left side instead of subtracting it, giving 6x = 6. 22 adds 8 to 14 instead of subtracting it and never divides 2x = 22 by 2.

Correct answer: x = 2 and x = 3

x = 2 and x = 3 is correct: the trinomial factors as (x - 2)(x - 3) = 0. x = 1 and x = 6 use the factor pair 1 and 6, whose product is 6 but whose sum is 7, not 5. x = -2 and x = -3 take the numbers in (x - 2)(x - 3) without changing their signs. x = -1 and x = -6 make both of those slips, using the pair 1 and 6 and then taking the numbers in (x - 1)(x - 6) without changing their signs.

Correct answer: 15

15 is correct: n + (n + 1) + (n + 2) = 3n + 3 = 48, so 3n = 45 and n = 15. 16 is 48 divided by 3, the middle integer, not the smallest. 17 is the largest of the three integers, not the smallest. 8 treats the numbers as n, 2n and 3n, giving 6n = 48.

Correct answer: 8x - 6

8x - 6 is correct: 6(2x - 1) = 12x - 6, and 12x - 6 - 4x = 8x - 6. 16x - 6 adds 4x instead of subtracting it. 8x - 1 multiplies only the 2x by 6 and leaves the -1 unchanged. 16x - 1 makes both of those slips, computing 12x - 1 + 4x.

Correct answer: 4

4 is correct: cross-multiplying gives 15x = 6 times 10 = 60, so x = 4. 1 uses additive reasoning: 10 is 5 less than 15, so it takes x as 5 less than 6. 9 turns the second ratio upside down, solving x/6 = 15/10, so 10x = 6 times 15 = 90. 60 stops at 15x = 60 without dividing by 15.

Correct answer: A horizontal line

A slope of 0 means the rise is 0 for every run, so y never changes and the graph is a horizontal line. 'A vertical line' confuses a slope of 0 with an undefined slope, which is what a vertical line has. 'A line through the origin' confuses the slope with the y-intercept; the slope says nothing about where the line crosses the y-axis. 'A line that rises from left to right' describes a positive slope.

Correct answer: 3

3 is correct: subtracting 7 from both sides gives -2x = -6, and dividing by -2 gives x = 3. -4 adds 7 to 1 instead of subtracting, giving -2x = 8. 4 rewrites the equation as 2x = 6 and then subtracts 2 instead of dividing by 2. -3 divides -6 by -2 but gives the quotient a negative sign.

Correct answer: 5

5 is correct: 3x - 4 = 11, so 3x = 15 and x = 5. 29 substitutes 11 for x and computes g(11) instead of solving g(x) = 11. 7/3 subtracts 4 from 11 instead of adding it, giving 3x = 7. 15 stops at 3x = 15 without dividing by 3.

Correct answer: (1, 3)

(1, 3) is correct: substituting x = 1 gives y = -1 + 4 = 3. (1, 5) drops the negative sign on x and uses y = x + 4. (1, -5) changes the sign of the 4 and uses y = -x - 4. (1, -3) makes both sign slips and uses y = x - 4.

Correct answer: 1

1 is correct: 2(5) - 3^2 = 10 - 9 = 1. 4 doubles b instead of squaring it, computing 10 - 6. 49 subtracts first and then squares, computing (10 - 3)^2. 16 reads 2a as the two-digit number 25, computing 25 - 9.

Correct answer: 18

18 is correct: n + 12 = 30, so n = 30 - 12 = 18. 28 regroups in the subtraction but forgets to reduce the tens digit from 3 to 2. 2.5 reads 'increased by' as multiplication and solves 12n = 30. 42 adds 12 to 30 instead of subtracting it.

Correct answer: x^5

x^5 is correct: when dividing powers of the same base, subtract the exponents, 8 - 3 = 5. x^-5 subtracts in the wrong order, 3 - 8, which is the result for x^3 divided by x^8. x^11 adds the exponents, which is the rule for multiplying powers, not for dividing them. x^24 multiplies the exponents, which is the rule for raising a power to a power.

Correct answer: x = 7 or x = -7

x = 7 or x = -7 is correct: both 7 and -7 are 7 units from 0, so both have an absolute value of 7. x = 7 gives only the positive solution and misses -7. x < -7 or x > 7 solves the inequality |x| > 7, not the equation. x > 7 confuses the equation with that inequality and also keeps only the positive side.

Correct answer: d/5

d/5 is correct: the cost of one notebook is the total cost divided by the number of notebooks. 5/d inverts the ratio and gives notebooks per dollar. 5d multiplies the total cost by the number of notebooks instead of dividing. 1/(5d) multiplies and then inverts, so it makes both of those slips.

Correct answer: 10

10 is correct: subtracting 3 gives 0.5x = 5, and dividing by 0.5 doubles 5 to give x = 10. 22 adds 3 to 8 instead of subtracting it, giving 0.5x = 11. 13 divides the 8 by 0.5 but not the 3, writing x + 3 = 16. 2.5 halves 5 instead of dividing it by 0.5, which doubles it.

Correct answer: y = 3x - 4

y = 3x - 4 is correct: parallel lines have equal slopes, and this line has slope 3, like y = 3x + 1. y = -3x - 4 has the opposite slope. y = x/3 - 4 uses the reciprocal of the slope, 1/3. y = -x/3 - 4 uses the negative reciprocal, which gives a perpendicular line, not a parallel one.

Correct answer: 16

16 is correct: with the numbers x and 4x, x + 4x = 20, so x = 4 and the larger number is 4x = 16. 4 is the smaller number, x, not the larger. 15 divides 20 by 4 instead of 5, taking the smaller number as 5 and the larger as 20 - 5. 12 is the difference between the two numbers, 16 - 4.

Correct answer: 14

14 is correct: (4 + 3)(4 - 2) = 7 times 2 = 14. 26 multiplies 7 by 4 and then subtracts 2, ignoring the second pair of parentheses. 42 changes x - 2 to x + 2 and multiplies 7 by 6. 30 expands the product with a middle term of 5x instead of x, giving 16 + 20 - 6.