Verb form; Rhetorical construction
This sentence is well-formed. It appropriately uses the construction to try
to rather than the common yet idiomatically inappropriate to try and. It also
uses the idiomatically correct construction recover . . . from.
A. Correct. This choice is correct for the reasons discussed above.
B. This choice uses the idiomatically incorrect construction to try and.
C. This choice suggests that what is prohibitively expensive is trying to
recover uranium . . . rather than the process of recovering uranium itself.
D. To try for is idiomatically incorrect, as is the recovery . . . out of.
E. To try to do—as opposed to to attempt, for example—is awkward and
unnecessarily wordy.
The correct answer is A.

虛擬語氣，主句用将来时，从句用一般现在时

我比他们吃的苹果多，这句话没毛病啊

1/3....1 2^n是4的倍数

答案没错，因为说了至少参加一场课程， 画出文氏图就发现，只要下午没上课的一定都是只去上午上课的人。

whether讨论的是是否会发生，没有预设已经发生了，不需要虚拟语气；what讨论的是如果发生了会有什么影响，预设已经发生，需要虚拟语气

根据原文内容一步步往下看，选出答案，容易混淆：对于build strategy，应为individual比较有效

到底是核桃小，还是产量小？？

思维定势了！上来第一个首先要确定的永远是单复数！！瞬间排出ABC，再用平行排除d。至于by far ,还有from 都是锦上添花。一定先看单复数！不要看到not only 就没有耐心了！

条件一：把w+y看成是一个负数为a, 把x+y看成是另一个负数为b, a-b=w-y，试想一下，两个负数相减，我们不能并不能判断是大于零还是小于零，也就无法得出w和y的大小了。（我觉得这样理解比较清楚）
条件二：就很明显了，直接给出y和w的关系

as在这里作为连词表原因！不要想当然当成比较!看见that就瞎排除。that作为定语，后面是组成了完整的句子的！审题不仔细！

which 需要担任成分！！