狒狒52

52. Birds need so much food energy to maintain their body temperatures that some of them spend most of their time eating. But a comparison of a bird of a seed-eating species to a bird of a nectar-eating species that has the same overall energy requirement would surely show that the seed-eating bird spends more time eating than does the nectar-eating bird, since a given amount of nectar provides more energy than does the same amount of seeds

The argument relies on which one of the following questionable assumptions

A.        Birds of different species do not generally have the same overall energy requirements as each other

B.        The nectar-eating bird does not sometimes also eat seeds

C.        The time it takes for the nectar-eating bird to eat a given amount of nectar is not longer than the time it takes the seed-eating bird to eat the same amount of seeds

D.       The seed-eating bird does not have a lower body temperature than that of the nectar-eating bird

E.        The overall energy requirements of a given bird do not depend on factors such as the size of the bird, its nest-building habits; and the climate of the region in which it lives

我觉得题目问的是这个argument依赖下面哪个假设，如果依赖c的话，n鸟吃一定数量的nectar的时间不长于s鸟吃一定数量的seed，也就是n鸟吃的要比s鸟快，至少一样，但如果这样的话，问题里说的n鸟用在吃nectar的时间要比s鸟少的原因是因为n鸟吃得快从而有可能吃的数量比s鸟多，而不可能是因为单个nectar的能量大了，而这样就削弱它的论述了，所以文章不能依赖这个假设啊？谢谢nn解答

A little bit stange.the question needs an questionable assumption.

first it should be an assumption.

since the engery they need is the same and nest provides much more nutritions ,it takes less time.

C is the answer that express the same meaning of the question.

还是不明白啊，能不能解释的再清楚一些阿，谢谢！

我觉得c的话，n鸟takes less time，所以吃得快，这样的话，题目说的同样能量需求的情况下，n鸟用较少的时间能得到和s鸟相同的能量值，这样的少就有可能是因为吃的快，而不是因为nectar能量多了，因为如果nectar含能量少的话，但由于n鸟吃得快而且多，所以能补偿nectar比seed少的那部分能量，所以就是削弱了，请nn帮我reasoning一下，谢谢

想太复杂

可以看作一个数学等式：　消耗的总能量＝食物数量×食物的单位能量＝（鸟的进食速度×进食时间）×食物单位能量

题目中高速我们，食物的单位能量一样，说鸟A消耗的能量比鸟B大，那么也就是说A的（鸟的进食速度×进食时间）比B大。题目的结论是A要多吃，就是A进食时间比B长。那么假设就是清楚了，这个等式变化的前提假设就是剩下的一个变量是不变的－－－进食速度。