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

B和C好像都有点道理，很难取舍啊

大家说呢 应该选哪个呀~

C

提干是说因为两种鸟需要的能量一样，而等量的nectar比seeds提供的能量多，所以吃seeds的鸟比吃nectar的鸟花更多的时间在吃上。

前提是两种鸟吃东西的速度差不多 Amount=速度*时间*能量。提干告诉你A相等，E1〉E2，得出的结论是T1<T2，要一定成立的前提只有V1和V2差不多。