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.

These days, publishers in Ramistan of glossy Western-style magazines rarely need to worry about interference from the government — the magazines’ content promotes consumption, and convincing Ramistan’s emerging middle class to spend their money is a key component of domestic policy. 想问选项A的and convincing是修饰谁的呢？修饰content的话为什么可以在前面加and？ 选项C为什么语法不正确呢？

plums are 75% water. prunes are 15% water. how much water must be evaporated for x kg of prunes? 这是我今天考场上的题，好像做错了。我乱选了（85x/15） 其他选项有各种 25x/85，15x/75什么的。应该怎么做？

一辆车，车轮上有一点离圆心 d cm，车子前进 D cm，问该点距离/车子前进的距离？ 1. d等于一个值 2. D等于一个值

Shoppers at Retailer R who purchased substitute items from other manufacturers on DayI paid a total amount that was approximately 78 of the total shoppers would have paid had each of them been able to purchase ProductXon Day 1. “was 和 would have paid ”都在一个从句里，怎末会有两个谓语动词？“had each of them been able to...”这部分是跟谁啊？看不懂

On his drive to work, Leo listens to one of three radio stations, A, B, or C. He first turns to A. If A is playing a song he likes, he listens to it; if not, he turns to B. If B is playing a song he likes, he listens to it; if not, he turns to C. If C is playing a song he likes, he listens to it; if not, he turns off the radio. For each station, the probability is 0.30 that at any given moment the station is playing a song Leo likes. On his drive to work, what is the probability that Leo will hear a song he likes? 这个题目的0.3为什末代指在A station 播放到了自己喜欢的？不太理解0.3到底指的是甚麽

提问叶老师，这个题我不太理解为什么appear要用单数？ D选项，what 指什么？from what 这个倒装正常语序应该怎么写？

等腰直角三角形的周长为：16+16√2 ；问斜边的长度 等腰直角三角形的非直角边一样长：那设为x 所以斜边就为（根据勾股定理）x√2 所以周长：x+x+√2 x=16+16√2 2x+√2 x=16+16√2 X=8√2 斜边就等于：16 问题：X=8√2 是怎么算出来的？

为什么算到这一步(3^2-2^2)(3^2+2^2)(3^4+2^4)就能直接算答案了（答案:5x13x97），难道有4次方的地方不继续化简吗？我怎么知道要把公式简化到哪一步？

老师好 我这道题的方法就是解二次方程，只有唯一正解才能证明是充分的。（我发现很多应用题都是这样）但是我发现解二次方程很浪费时间，考试的时候可能没那么充分的时间，怎么办呢？这道题还有更好的方法吗？谢谢老师