og-102 b,d

102. Although migraine headaches are believed to be caused by food allergies, putting patients on diets that eliminate those foods to which the patients have been demonstrated to have allergic migraine reactions frequently does not stop headaches. Obviously, some other cause of migraine headaches besides food allergies much exist.

Which of the following, if true, would most weaken the conclusion above?

(A) Many common foods elicit an allergic response only after several days, making it very difficult to observe links between specific foods patients eat and headaches they develop.

(B) Food allergies affect many people who never develop the symptom of migraine headaches.

(C) Many patients report that the foods that cause them migraine headaches are among the foods that they most enjoy eating.

(D) Very few patients have allergic migraine reactions as children live migraine-free adult lives once they have eliminated from their diets foods to which they have been demonstrated to be allergic.

(E) Very rarely do food allergies cause patients to suffer a symptom more severe than that of migraine headaches. A

答案是A

虽然B,D 没有解决文中所提出的疑问，但是确实有事实在的啊，逻辑题不要求一定能推翻原文中的论述吧，换句话说，削弱不要求是充分的，只要是必要的就行了吧。换句话说你说A对，我想不出驳倒你逻辑的办法，我举出例子来证明我的观点，这难道不是对你的一种削弱吗？

请牛牛指教

我想思路应该是这样：B承认了食物过敏导致许多从未得过偏头痛的人引起偏头痛。但是没有提及是否有其他的原因也会引起偏头痛。所以没有削弱论点。

我也选了D，是不是因为它虽然是事实，但是和题目没有很大关系。而且OG的解释也和题目不符。头疼！

1、题目原义：虽然偏头痛被认为是由食物过敏引起的，但是让病人遵循去掉证实经常引起偏头痛的食物的菜单也不能减缓病情。显然，除了食物过敏之外，还有其他引起偏头痛的原因存在。

2、我的理解是： 为了削弱结论，那么先应该削弱结论的根据；题目的根据就是基于“取出引起偏头痛的食物但是没有减轻病情”，那么A提供的“大多普通食物引起的过敏都在几天后才反应，使得观察进食特定食物的病人和他们病情发展之间的关系非常困难”，就是削弱结论的根据。当然，结论的根据没有使用时间副词修饰，我认为是有一点不够严谨。

另外，我也认为OG的解析不可理喻，它的解析好像否定A，认为A是支持题目的根据并且产生结论。

不知我的理解对不对，请nn们指教。