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.

老师例5，7的平方49，没有超过100啊，为什么不能选？

老师，这道题你换了好几次思路，真的没听懂！谢谢！

老师这道题没懂，我也不会拆分！

老师这个是怎么解出来的？拆分？这么大的数不会拆哦

老师，这里不懂条件1怎么算出来的， 40怎么来的？谢谢！

PS：|nx-8|≤4，有多少个整数n使得恰好只有2个整数解x？ 求问may老师

老师，这里看不懂二分之Q减一是什么？

老师例7的A怎么能成立呢？把2带进去，一个方程俩未知数啊？

讨论的71那三个情况不是3的倍数？70那俩是三的倍数？213能被三整除啊，其他不能整除怎么70那些都是3的倍数呢？谢谢哦！

我觉得这道题应该选E，因为当ab同时大于1，原命题成立，当ab同时大于0小于1，原命题不成立