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.

第8题的思路是以BC为底，从F向BC做垂线，跟BC交点H，FH为三角形FBC的高。然后三角形BFH跟三角形BDC相似，h：30=BF：BD，但是BF长度未知，望老师解答。

求问此题：DS：一个矩形地毯问面积是否大于160？ 条件1：对角线>21 条件2：至少有一条边大于8 谢谢！

求问此题的详细解法。谢谢老师~！

下面那个圆的半径我求不出来。请老师答疑！谢谢！

请问这道题是选E吗（答案我给忘了）？一个数N是否能被4！的三次方整除 1）这个数能被6！的二次方整除 2）这个数能被9！整除

5^500 + 5^501 + 5^502 + 5^503 最大的质因子是多少？求具体解法！谢谢老师！

求问此题：一个正方体，选三条不在同一顶点的棱涂成红色，问有几种方法？我的计算过程是C(12,1)*C(7,1)*C(2,1)=168.不知道思路正确与否，请老师答疑解惑。谢谢！

此题求解：DS：3个数，问中位数是否大于平均数？ 条件1：最大数和最小数之和大于中位数； 条件2：最大数=450+平均数，最小数=平均数-150 谢谢！

一个正方体，选三条不在同一顶点的棱涂成q红色，问有几种方法？ 请may回答 我算的是（ C3 12 ）-8