陆旭老师，我有一些做过的assumption题目取非的句子搞不清，你能帮忙看下吗(不说这道题目的解题思路，单纯就是取非问题，特别是双重否定或者从句里面有否定词） 1.No part of a person’s brain that is damaged by a stroke ever recovers.---> some 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.这个句子我不太会取非，正过来说这个句子就是Impairment of linguistic capabilities occurs in people who have suffered any damage to any language center of the brain.那么我取非是Impairment of linguistic capabilities occurs in people who have not suffered any damage to any language center of the brain. 3.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. 取非If there are language centers on the left side of the brain, any serious stroke affecting that side of the brain damages nothing of them. 4.这题出现两个not The collection fee will not significantly affect the purchasing power of most residents, even if their households do not reduce the amount of trash they put out. 我取非直接去前面的not: The collection fee will significantly affect the purchasing power of most residents, even if their households do not reduce the amount of trash they put out. 5.这个也差不多 Not all steel producers were unaffected by country A’s newly imposed tariffs. 我取非All steel producers were unaffected bycountry A’s newly imposed tariffs. 6.There are no plants native to western Africa that, if domesticated, could serve as staple food crops. 这个if domesticated是不是可以不管，直接改成There are some plants native to western Africa that, if domesticated, could serve as staple food crops.

想要请教一下陆旭老师用您的方法怎么解这道题？谢谢！

这里的from，换成below跟above的话，要怎么理解？网课上说的不太清楚，可以再详细说一下吗？

麻烦老师详细分析下ABC选项，以及为什么要用corresponding，谢谢

这个题我一开始选的E，做题的时候完全摸不到头绪，感觉每个选项都不太好，麻烦老师详细分析下每个选项，谢谢

DE有哪些错误

这道题选A，但我觉得光是A没办法确定，求老师讲解，谢谢！

这道题我总觉得两个单独都可以，但答案选B，求老师梳理一下，谢谢！

请问这里的factor是根的意思吗？只凭A的话应该只能确定x和k都是根吧，是怎么确定x-k也是根的呢？

请问老师这个怎么只凭A就能算出来呀？

想要请教一下老师这道题怎么写？