假设题的另一种解题思路 - 由FeiFei120谈起

先看一下题目：狒狒-Test7-120

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

这题的标准答案应该是D，但是偶在做题的时候也选择了A，相信不少xdjm们也和偶一样，被ETS引入了歧途，这里A错误的原因是他对原文的结论是一个充分条件而非必要条件（assumption的正确答案对原文是必要条件）。

这里偶想谈的一点感受是，D的答案其实一种他因排除；偶在feifei的讲义中找了一下，发现对于假设题基本上都是采用搭桥的方式进行解决（偶就是在此题利用搭桥就被引入A这个错误选项了）。但是在总结这题的时候，偶突然想到，assumption题目的正确答案取非对原文结论削弱，而对于削弱题我们常有两种方法，1）断桥；2）排除他因；那么事实上，assumption题相应的也至少应该有两种解决方法，而且正好是和削弱题相反：1）搭桥；2）唯一原因

我们常用的是第一种，而且第二种情况出现的极少，但是我们也不得不提防ETS突然来这么个狠招，呵呵，再回过头来看狒狒的这道题目，答案就一目了然，D正是说明了体操运动作为原因的排他性（唯一性），所以就是正确答案了。

望各位NN指正！