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.

为什么critique和envisioning不算并列？划线部分做同位语作用，为何不能用起伴随作用的DE？as well as是否既可以用在两者比较又可以用在三者？

请数学老师解答

请问数学老师 条件中 each more than 3 feet from the nearest wall 这个条件有什么用？再说下思路 谢谢老师

请问数学老师 条件2怎么可以快速推算结果

老师 我不太懂什么k一定是4的倍数呢？

ken老师这道题目答案对吗？为什么说两个条件中的方程是同一个方程啊，我算出来不一样，当条件1&2同时存在时，两个方程是有两个交点，应该就是可以判断出（a,b)的值吧？

请问数学老师 这个题如何在短时间内快速得出答案

ken老师 这道题目黄色部分我不太明白，An和n各自代表什么意思？我以为An代表的整数列所有数的合，那n不可能小于100呀，好奇怪

麻烦金老师回答，主要的困惑在于AB两个选项。一个that位置的不同，和will 和 would 的不同。刚开始我的思路是旅客会更多的使用旅行机构这件事是一个预测，没发生的，虚拟语气所以就错选了B.will 和would 的区别是 will 表达的感觉更确定一点吗？

麻烦金老师回答，这题看到DIGGING 这个动作是人发出的 不可能是化石发出的，排除AB ，C 里面的it 指代不是很清楚。对比DE， 这个化石来自那里这个部分的内容比较长所以D 选项是用了一个从句来说明的意思吗？就是关于DE选项的appears 和 APPEAR 这个差一点我不是很清晰，还是说D这个答案的what 这个选项引导的从句直接修饰到bones上，所以胜出？