SAT Reading & Writing: Hard Rhetorical Synthesis (Drill 27)

Question 1. The student wants to present the study's finding about strand strength. Which choice most effectively uses relevant information from the notes to accomplish this goal?

• A) Workers soak the cocoons in hot water so the softened sericin lets each filament unwind smoothly without snapping partway through the reeling.
• B) Each cocoon is wound from one continuous filament of fibroin.
• C) The pupa inside is killed by the heat before the moth can emerge, since a moth chewing its way out would break the long silk filament into short and far less useful lengths.
• D) The study found that filaments reeled together from several cocoons made one strand far stronger than any filament alone. ✓

Explanation: Choice D is the best answer. The sentence reports the measured result, that combining several filaments yields a strand stronger than a lone filament, which is the finding the goal asks for. Choice A describes the hot-water soak, a processing step rather than the strength finding. Choice B gives the makeup of a single filament, a structural detail rather than the result. Choice C explains why the pupa is killed, a separate step that says nothing about strength.

Question 2. The student wants to define what a sextant is for readers new to the term. Which choice most effectively uses relevant information from the notes to accomplish this goal?

• A) A sextant is a handheld instrument that uses two mirrors to measure the angle between the horizon and a star or the sun. ✓
• B) The angle that the instrument measures between a chosen body and the horizon line is the quantity known to navigators as the altitude of that body.
• C) The instrument's name comes down from the Latin word for "one-sixth," because the arc of its graduated scale spans sixty degrees, a sixth of a full circle.
• D) A sextant's altitude reading, paired with the exact time and a set of reference tables, fixes a line of the ship's own position at sea.

Explanation: Choice A is the best answer. The sentence gives the defining features, a handheld two-mirror instrument that measures the angle between a body and the horizon, which is what the goal calls for. Choice B defines altitude, a related term rather than the instrument itself. Choice C explains the origin of the name, a detail rather than the core definition. Choice D states what the reading lets a navigator do, a function rather than a definition.

Question 3. The student wants to explain how a small driving gear produces more torque at the output. Which choice most effectively uses relevant information from the notes to accomplish this goal?

• A) An idler gear set between the two reverses the output's direction of rotation while leaving the overall gear ratio completely unchanged.
• B) A gear ratio is found by dividing the driven gear's tooth count by the tooth count of the driving gear.
• C) A small driver turning a large driven gear slows the output but raises its torque, since the product of speed and torque holds nearly constant. ✓
• D) A small driver turning a large driven gear speeds the output shaft up, while the torque that finally reaches the load drops away in steady proportion.

Explanation: Choice C is the best answer. The sentence explains the mechanism, that slowing the output raises torque because their product holds nearly constant, which is the process the goal asks about. Choice A describes the idler gear's role, a different effect than the torque increase. Choice B defines how the ratio is calculated, a formula rather than the process. Choice D claims the output speeds up, reversing what a large driven gear actually does.

Question 4. The student wants to convey why lichens are valuable as long-term indicators of air quality. Which choice most effectively uses relevant information from the notes to accomplish this goal?

• A) A lichen is a partnership between a fungus and an alga or cyanobacterium that lives together as a single body.
• B) Because lichens take in airborne substances directly across their surfaces and live for years, their slow-changing condition records a place's air quality, letting a survey map the pollution. ✓
• C) Of all the air pollutants, sulfur dioxide is the one to which lichens prove the most sensitive.
• D) Having neither true roots nor any waxy cuticle to seal them off, lichens take in their water and whatever airborne substances happen to reach them right across the whole of their outer surface.

Explanation: Choice B is the best answer. The sentence states why lichens matter as monitors, that their direct absorption and long lives make them a lasting record that maps air quality, which is the significance the goal asks for. Choice A defines the organism, background rather than its value as an indicator. Choice C names the pollutant they react to most, a narrow detail rather than the significance. Choice D explains how they absorb pollutants, a mechanism rather than why they are useful.

Question 5. The student wants to make a general statement about how corals build reefs. Which choice most effectively uses relevant information from the notes to accomplish this goal?

• A) As old polyps die off, their hard skeletons cement together and slowly accumulate, until over many thousands of years the stacked layers build a reef.
• B) Algae living inside a coral's tissue feed it by photosynthesis and so speed up its skeleton-building.
• C) More acidic seawater leaves the corals less dissolved carbonate, which slows their skeleton-building and can even dissolve existing skeletons away.
• D) Reef-building corals lay down hard aragonite skeletons that cement together as polyps die, piling up over millennia into a reef. ✓

Explanation: Choice D is the best answer. The sentence states the broad process, that corals deposit aragonite skeletons that accumulate into a reef over long spans, which is the generalization the goal calls for. Choice A captures only the accumulation, leaving out how each skeleton is laid down in the first place. Choice B highlights the algae's role, one contributing factor rather than the whole. Choice C focuses on acidification, a single threat rather than the general building process.