請教黃金閱讀Begging by Nestlings - 英檢

Paragraph 6：As these experiments show, begging apparently provides a signal
of need that parents use to make judgments about which offspring can benefit
most from a feeding. But the question arises, why don't nestlings beg loudly
when they aren't all that hungry? By doing so, they could possibly secure
more food, which should result in more rapid growth or larger size, either of
which is advantageous. The answer lies apparently not in the increased energy
costs of exaggerated begging—such energy costs are small relative to the
potential gain in calories— but rather in the damage that any successful
cheater would do to its siblings, which share genes with one another. An
individual's success in propagating his or her genes can be affected by more
than just his or her own personal reproductive success. Because close
relatives have many of the same genes, animals that harm their close
relatives may in effect be destroying some of their own genes. Therefore, a
begging nestling that secures food at the expense of its siblings might
actually leave behind fewer copies of its genes overall than it might
otherwise.

12. According to paragraph 6, which of the following explains the fact that a
well-fed nestling does not beg loudly for more food?
○ There is no benefit for a nestling to get more food than it needs to
survive.
○ By begging loudly for food it does not need, a nestling would
unnecessarily expose itself to danger from predators.
○ If a nestling begs loudly when it is not truly hungry, then when it is
truly hungry its own begging may be drowned out by that of its well-fed
siblings.
○ More of a nestling's genes will be passed to the next generation if its
hungry siblings get enough food to survive.

答案是4，這題我白痴的選了2…可是我依然看不出為何要選4…
麻煩各位幫不才的我解答了…謝謝^^"

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