The following text is from a science article about animal migration.
Arctic terns hold the record for the longest annual migration of any animal. Each year, these small seabirds travel from their Arctic breeding grounds to Antarctic waters and back—a round trip of approximately 44,000 miles. They follow a zigzag route that takes advantage of global wind patterns, which helps them conserve energy during their remarkable journey.
Which choice best describes the function of the last sentence?
It provides an example that contradicts the passage's main claim.
It explains a strategy that enables the behavior described earlier.
It introduces a new species for comparison.
It questions the accuracy of the distance measurement.
Correct Answer: B
Choice B is the best answer. The last sentence explains how Arctic terns accomplish their long migration—by using wind patterns to conserve energy (a strategy enabling the behavior).
- Evidence: The text describes the "longest annual migration" (behavior). The last sentence says they "follow a zigzag route that takes advantage of global wind patterns" to "conserve energy."
- Reasoning: This explains how they manage the feat described in the first sentence.
- Conclusion: The function is to explain the enabling strategy.
💡 Strategy: Ask "What does this sentence do?" It answers "How do they do it?"
Choice A is incorrect because it supports, not contradicts the claim. Choice C is incorrect because no new species is introduced. Choice D is incorrect because it doesn't question the distance.