ASVAB ASVAB Paragraph Comprehension and Inference 4 — Questions and Answers
Question 1: Read the passage: 'The bald eagle was removed from the endangered species list in 2007 after decades of conservation efforts. Populations had plummeted due to hunting and the pesticide DDT, which caused eggshell thinning. Once DDT was banned in 1972 and legal protections were strengthened, eagle numbers rebounded dramatically.' What can be inferred about DDT's effect on eagles?
- DDT directly poisoned adult eagles, reducing their lifespan
- DDT prevented successful reproduction by weakening eggs before hatching (Correct answer)
- DDT caused eagles to abandon their nesting territories permanently
- DDT reduced the fish populations that eagles depended on for food
Correct answer: DDT prevented successful reproduction by weakening eggs before hatching
The passage states DDT caused eggshell thinning, meaning eggs broke before hatching, which prevented reproduction.
Question 2: Read the passage: 'A thermostat works by using a bimetallic strip — two metals bonded together that expand at different rates when heated. As temperature rises, one metal expands faster than the other, causing the strip to bend and break an electrical circuit, shutting off the heat. When it cools, the strip straightens, reconnecting the circuit.' What happens when the room reaches the set temperature?
- The bimetallic strip melts and needs replacing
- The strip bends and breaks the circuit, turning off the heating system (Correct answer)
- The strip straightens, allowing more heat to flow into the room
- An electrical surge causes the thermostat to reset automatically
Correct answer: The strip bends and breaks the circuit, turning off the heating system
The passage explains that rising temperature causes the strip to bend and break the circuit, shutting off the heat.
Question 3: Read the passage: 'Many ancient civilizations built their cities near rivers. Rivers provided fresh water for drinking and irrigation, served as highways for trade, and deposited nutrient-rich silt during floods that made surrounding farmland extremely fertile. However, cities also faced the constant threat of devastating floods.' What is the most accurate inference from this passage?
- Ancient people were unaware of the dangers rivers posed
- Rivers were too dangerous for ancient civilizations to rely upon
- Ancient civilizations accepted flood risks because rivers offered vital benefits (Correct answer)
- Most ancient cities were eventually destroyed by flooding
Correct answer: Ancient civilizations accepted flood risks because rivers offered vital benefits
The passage shows rivers provided multiple essential benefits, implying civilizations accepted the flood risk as a worthwhile trade-off.
Question 4: Read the passage: 'Caffeine works by blocking adenosine receptors in the brain. Adenosine is a chemical that builds up during waking hours and promotes feelings of drowsiness. When caffeine occupies these receptors, adenosine cannot bind to them, so the drowsy signal is never sent. However, adenosine continues to accumulate, which is why fatigue hits hard once caffeine wears off.' What does the passage imply about the 'caffeine crash'?
- Caffeine causes the body to produce extra adenosine as a side effect
- The crash occurs because all adenosine that built up is suddenly able to act (Correct answer)
- Caffeine permanently damages adenosine receptors over time
- The brain stops producing adenosine while caffeine is active
Correct answer: The crash occurs because all adenosine that built up is suddenly able to act
The passage states adenosine keeps accumulating, so when caffeine wears off, all that built-up adenosine can finally bind to receptors at once.
Question 5: Read the passage: 'In the 1800s, the Pony Express delivered mail across nearly 2,000 miles of American frontier in about 10 days — a remarkable achievement for the era. Yet the service lasted only 18 months before shutting down. Just two days after the Pony Express began operations, Congress approved funding for the transcontinental telegraph.' What is the most logical reason the Pony Express failed?
- Riders found the route too dangerous and quit in large numbers
- The telegraph provided faster communication, making mail delivery obsolete for urgent messages (Correct answer)
- The service was never profitable because postage rates were set too low
- Horses could not maintain the pace required across the full 2,000-mile route
Correct answer: The telegraph provided faster communication, making mail delivery obsolete for urgent messages
The timing of the telegraph's approval — just two days after the Pony Express launched — strongly implies the faster technology made it unnecessary.
Question 6: Read the passage: 'Coral reefs cover less than one percent of the ocean floor, yet they support approximately 25 percent of all marine species. Scientists often call them the 'rainforests of the sea.' Rising ocean temperatures cause coral bleaching, a stress response in which corals expel the algae living in their tissues, turning white. Without these algae, corals can starve.' What can be concluded about coral bleaching's broader impact?
- Bleaching only affects the visual appearance of reefs without harming marine life
- If bleaching kills corals, it could threaten the survival of a quarter of all marine species (Correct answer)
- Coral bleaching is a natural cycle that reefs recover from within a few weeks
- Rising temperatures cause algae to overgrow reefs, smothering the corals beneath
Correct answer: If bleaching kills corals, it could threaten the survival of a quarter of all marine species
Since 25% of marine species depend on coral reefs, and bleaching can kill corals by starvation, massive biodiversity loss would follow widespread bleaching.
Question 7: Read the passage: 'A placebo is an inactive substance — such as a sugar pill — given to patients in clinical trials. Remarkably, some patients who receive placebos show genuine improvement in their symptoms, a phenomenon called the placebo effect. Researchers must account for this effect when evaluating whether a new drug actually works.' Why do researchers use placebos in drug trials?
- To save money by giving some patients cheaper treatments
- To ensure some patients improve so the trial appears successful
- To distinguish between improvement caused by the drug and improvement caused by belief alone (Correct answer)
- To test whether patients can correctly identify which treatment they received
Correct answer: To distinguish between improvement caused by the drug and improvement caused by belief alone
Placebos allow researchers to separate real drug effects from improvements caused purely by the expectation of treatment.
ASVAB ASVAB Paragraph Comprehension and Inference 4
Read the passage: 'The bald eagle was removed from the endangered species list in 2007 after decades of conservation efforts.
Populations had plummeted due to hunting and the pesticide DDT, which caused eggshell thinning.
Once DDT was banned in 1972 and legal protections were strengthened, eagle numbers rebounded dramatically.' What can be inferred about DDT's effect on eagles?