For most people, the left half of the brain controls linguistic capabilities, but some people have their language centers in the right half. When a language center of the brains is damaged, for example, by a stroke, linguistic capabilities are impaired in some way. Therefore, people who have suffered a serious stroke on the left side of the brain without suffering any such impairment must have their language centers in the right half.
Which of the following is an assumption on which the reasoning in the argument above depends?
No part of a person’s brain that is damaged by a stroke never recovers
Impairment of linguistic capabilities does not occur in people who have not suffered any damage to any language center of the brain.
Strokes tend to impair linguistic capabilities more severely than does any other cause of damage to language centers in the brain.
If there are language centers on the left side of the brain, any serious stroke affecting that side of the brain damages at least one of them.
It is impossible to determine which side of the brain contains a person’s language centers if the person has not suffered damage to either side of the brain.
B. Denial test: Impairment of linguistic capabilities occur in people who have not suffered any damage to any language center of the brain.不能削弱原文,与原文结论无关,因为原文讨论的是people who have suffered stroke,没有讨论people who have not suffered any damage to any language center of the brain
C. 没有讨论More severe
D. 搭桥。如果大脑语言中心在左边,任何中风都会破坏至少其中之一的语言中心。 Denial Test: 任何中风都不会破坏任何的语言中心,削弱结论“左脑中风,语言能力没被削弱,那么语言中心在右脑”,有可能语言中心在左脑。所以为Assumption
我的理解是这样的:从stroke到impairment有两步,第一步是stroke 必须要造成damage ,第二步是damage必须要造成impairment.两个都是前提。但是文中已经肯定了第二个前提:When a language center of the brains is damaged, for example, by a stroke, linguistic capabilities are impaired in some way。所以只需点出第一个前提,即D。而B把双重否定去掉变成肯定后基本上就是重复原文已经肯定了的第二个前提,所以没什么意义。