费费120

120. In Europe, schoolchildren devote time during each school day to calisthenics. North American schools rarely offer a daily calisthenics program. Tests prove that North America children are weaker, slower, and shorter-winded than European children. We must conclude that North American children can be made physically fit only if they participate in school calisthenics on a daily basis.

Which one of the following is assumed in the passage?

A.        All children can be made physically fit by daily calisthenics.

B.        All children can be made equally physically fit by daily calisthenics.

C.        Superior physical fitness produces superior health.

D.       School calisthenics are an in indispensable factor in European children’s

E.        North American children can learn to eat a more nutritious diet as well as to exercise daily.

Why the answer is D.

The conclusion is American children are physically fit 能推出 daily calisthenics

The assumption is European children are physically fit 能推出 daily calisthenics

why?

谈谈我的理解

首先用排除法：C中的health，E中的to eat more nutritions diet在题干中没有出现过，因此不正确。而A、B基本等价，不可能同时对，所以只有D正确。

再来看看D。题干中的结论是北美的学生“只有（only if）”参加“school calisthenics”才能“be made physically fit”，是一个必要条件。而D中说“school calisthenics”是“indispensable factor”，不可缺少的，绝对必要的因素。所以判断D正确。