Question 139·Easy·Central Ideas and Details
Scientists tracking the common swift, a small migratory bird, recently attached lightweight sensors to several individuals. The data showed that once these swifts leave their European nesting grounds in late summer, they may remain airborne without landing for roughly ten months, gliding, feeding on insects, and even sleeping while aloft. Researchers say this nearly nonstop flight is unlike anything they have observed in other bird species.
According to the passage, what ability of the common swift surprised researchers?
For detail questions that start with phrases like "According to the passage," go straight back to the text and find the exact sentence or phrase that addresses the topic in the question (here, what surprised researchers). Look for clue words such as "researchers say," "unlike," or "surprised" that signal the relevant part. Then choose the option that paraphrases that specific detail and eliminate any answers that introduce new information, no matter how plausible or impressive they sound based on outside knowledge.
Hints
Find where the researchers react
Scan for where the passage mentions what researchers say or think. Focus especially on the sentence that includes the words "Researchers say..."
Look for a unique or unusual behavior
In that part of the passage, identify what behavior of the swifts is said to be "unlike anything" seen in other bird species. That unique behavior is what the question is asking about.
Match the idea, not the exact wording
Once you know what behavior surprised the researchers, pick the option that restates that same idea, even if it does not use the exact same words as the passage. Eliminate choices that describe abilities the passage never mentions.
Step-by-step Explanation
Understand what the question is asking
The question asks: "According to the passage, what ability of the common swift surprised researchers?" This means you must find a specific ability described in the passage that researchers found unusual or unlike other birds, not just any random impressive skill.
Locate the key part of the passage
Look at the part of the passage that mentions the researchers' reaction: toward the end, it says that after leaving their nesting grounds, the swifts stay in the air, gliding, feeding, and even sleeping while aloft. Then it adds that this "nearly nonstop flight" is unlike anything researchers have observed in other bird species. That phrase tells you what ability is surprising to them.
Match the specific ability to an answer choice
Now compare that detail to the answer options. The surprising ability is that the birds can keep flying almost all the time, for a very long stretch, without landing. Option D says, "It can remain in continuous flight for about ten months," which exactly matches the description of nearly nonstop flight after leaving their nesting grounds. Therefore, the correct answer is: It can remain in continuous flight for about ten months.