帮忙看下这道逻辑题

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 brain 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?

1. No part of a person’s brain that is damaged by a stroke ever recovers.
2. Impairment of linguistic capabilities does not occur in people who have not suffered any damage to any language center of the brain.
3. Strokes tend to impair linguistic capabilities more severely than does any other cause of damage to language centers in the brain.
4. 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.
5. 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.

选第4个..不明白啊

原文逻辑链:

serious stroke --> language centers --> impaired.

当然需要假设,  stroke 必须损坏了centers才能最后导致impaired, 如果没有损坏centers, 那不能得出原来结论.

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 brain 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.

 原文说的整体意思是：是一个什么玩意的哪一边有没有语言能力在谈。

 原文说的整体意思是：是一个什么玩意的哪一边有没有语言能力在谈。

 Which of the following is an assumption on which the reasoning in the argument above depends?

A.No part of a person’s brain that is damaged by a stroke ever recovers.

A说一个啥玩意被毁坏了，无关选项，没说语言能力

B.Impairment of linguistic capabilities does not occur in people who have not suffered any damage to any language center of the brain.
 

B说一个什么玩意不能发生在人，无关选各项，没说什么能力

C.Strokes tend to impair linguistic capabilities more severely than does any other cause of damage to language centers in the brain.

C说敲一个啥玩意比其他的毁坏更能啥玩意，重心不是在啥能力，无关选项。

D.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.

 D说任何的毁坏啊都能毁了他，如果一个啥玩意的能力在一啥地方。

E.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.

E说，这个决定不了的，哪边的啥玩意包含一啥能力，如果没毁了他。重心在哪边的啥玩意，无关选项。