Practice bank
Reading comprehension: identify the main idea
VerbalReading comprehensionMedium
Passage: "Karl von Frisch's decoding of the honeybee waggle dance showed that the angle of the dance relative to vertical encodes the direction of a food source relative to the sun, while the dance's duration encodes distance. Later research complicated this picture in productive ways: richer food sources provoke longer and more vigorous dances, so the dance conveys quality as well as location, and foragers weigh dance information against their own prior knowledge of a site, sometimes ignoring dances that point to familiar, depleted patches." The passage is primarily concerned with...
- Ademonstrating that von Frisch's interpretation of the waggle dance was fundamentally mistaken
- Bdescribing what the waggle dance communicates and how later findings refined that account
- Ccomparing the navigation abilities of honeybees with those of migratory birds
- Dexplaining the physiological mechanism by which bees produce the waggle dance
- Ewarning that declining bee populations threaten scientific study of the dance
Try it before you scroll. Two minutes on the clock, then commit to an answer.
Correct answer: B
Map the passage’s structure before reading choices. Sentence one: von Frisch’s decoding (direction and distance). Sentence two: later additions (quality, and foragers weighing dances against prior knowledge). Nothing is overturned; the later work is described as complicating the picture “in productive ways,” which means refinement, not rejection.
- (B) captures both halves: what the dance communicates (location, distance, quality) and how later findings refined the account (context-dependent use by foragers). Correct.
- (A) overstates: refinement is not refutation. The passage credits von Frisch’s decoding as the foundation.
- (C) introduces birds, which never appear.
- (D) asks about the mechanism producing the dance (muscles, neural control), which the passage never discusses; it is about what the dance means.
- (E) raises population decline, an idea with zero textual support.
Main-idea questions punish choices that are true-sounding but unsupported, and choices that match one sentence while missing the whole. (A) matches the later-research sentence but misreads its tone. (B) is the only option that covers both sentences with the right relationship between them.