Migratory songbirds breeding in Eurasia’s temperate forests depend on a summer flush of insects, particularly caterpillars, to f

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问题     Migratory songbirds breeding in Eurasia’s temperate forests depend on a summer flush of insects, particularly caterpillars, to feed themselves and their offspring. In some places, these caterpillars are emerging earlier in responses to rising global temperatures. In theory, the songbird could simply push up their departure from their winter quarters to catch the earlier flush of insect prey. If, however, the birds rely on a fixed cue such as increasing day length to begin flying north, they may be unable to adjust the timing of their migration. Precisely this disruption in the emergence of insects relative to the timing of songbird migration has been identified as the cause of a significant decline in populations of pied flycatchers in the Netherlands.
The primary function of the highlighted sentence is to

选项 A、refute the legitimacy of an earlier claim.
B、hypothesize about a response to a particular situation.
C、point out a distinction between two theories.
D、present an explanation for a shifting environment.
E、illustrate a problem by providing an example.

答案B

解析 a particular situation指的是“昆虫提前出现”,a response指的是“鸟类可以提前迁徙”,hypothesize对应第三句给出的理论推测,因此选项B正确。
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本试题收录于: GRE VERBAL题库GRE分类
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