Q52 ( I chose E, why C is the correct key?)

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 that does the nectar-eating bird, since a given amount of nectar provideds more energy than does the same amount of seeds

The arguement 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 somethings 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 depends on factors such as the size of the bird, its nest-building habits and the climate of the region in which it lives

前提1：seed－eating和nectar－eating的鸟儿需要同样多的能量

前提2：nectar比seed提供更多的能量

结论：seed－eating的鸟儿要花比nectar－eating的鸟儿更长的时间来摄取同

样的能量。

C说，鸟吃nectar的速度不比吃seed的速度慢。如果取非，就是鸟吃nectar的

速度比吃seed的慢，则虽然鸟需要更多的seed，但它们吃得更快，所以seed－

eating得鸟并不一定要花比nectar－eating得鸟更长的时间来摄取同样能量。

所以C去非对文章结论有削弱作用，就是答案。

E有太多无关信息，属于out of scope。