难道没有人觉得but要用平行吗，都在说C头重脚轻？凭啥他就一定头重脚轻了？我是觉得平行更重要，at present 和it may some day,更平行。

1.idiom, recover . . . from....是正确用法，CD错
2.idiom,to try to do是正确用法BD错
3.简洁表达，E的将recover前置，后面用的to try to do，do就代表recover，这个表达方式很不简洁。E错
4.句意推理，CD强调的是try会变得有意义，但是句意应该是recover会变得有意义。CD都错。
谢谢keeson小哥，时隔4个月在看，你说的对！

B. 根据逻辑应该是try to recover而不是try和recover两个并列。
C. Trying to recover uranium out of seawater主语过长，应该用形式主语it代替更好，而且recover A from B 为固定搭配。
D. To try for错误，其他错误同B。
E. 不是Recovering uranium from seawater 是值得试图去做的，而是 Trying to recover uranium out of seawater是值得做的

try to do XX 是值得做的 而非 do XX； A选项 to try to do 为实际的主语，也与后面的process对应

(B) Incorrect. “Try and recover” is incorrect. The point is to try to recover; “try” and “recover” are not two different actions.

(C) Incorrect. For the following reasons:

“Recover x out of y” is incorrect. The correct idiom is “recover x from y”.
With this option, “this process” of the non-underlined part will refer to “trying to recover uranium”. Logically, “this process” should refer to “recover uranium”.
(D) Incorrect. For the following reasons:

The first error of option C
“To try to recover uranium” is much better than “to try for the recovery of uranium”, just as “to try to reduce weight” is much better than “to try for the reduction in the weight”. The first construction emphasizes the action that is being tried.
(E) Incorrect. “To do” is incorrect. If we replace ‘do’ with ‘recover’, the redundancy is evident. “Recovering …. to try someday” would work.

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.

Recovering uranium from seawater may be worthwhile to try to do someday. = try to recover ... ----wordy

to try and recover is problematic

A选项it作形式主语，指代“to recover uranium from seawater”，句子核心也是它，可以写成“To recover uranium from seawater may someday be worthwhile to try”，说的是“也许有一天从海水中回收铀是值得一试的”； C项句子核心变成了trying（包括D的to try也是），意思是“试着从海水中回收铀也许有一天是值得的”； 这样比较显然A更合理，谈到平行的话，A的平行更贴切，but从句核心也是the process“从海水中回收铀”和前面对应，前面表语“worthwhile to try”和后面表语"expensive"对应。

B项 try 和recover不应该是and连接的平行关系，应该是try to recover
C项 recover A from B是固定搭配，不能换成out of
D项 try后面不与for搭配
E项 to do 多余

选项C：“out of seawater” suggests that uranium, in big volumes, is kept in sea and it just has to be taken out from there. Actually Uranium is processed out.

老师不是说了不要挑头重脚轻这种错误么，为什么还有人说头重脚轻啊，搭配不好这种

recover A from B

? C: out of 不对结合第2句。
this process [Trying to recover ] is expensive
Intended meaning:
this process [recovering ..[ is expensive.
在A里 It [to recover...] is worthwhile to try

用形式主语，避免头重脚轻。
E：recovering就是try to do中的to do，wordy

C头重脚轻

A与C相比不wordy

B 前面说是试着发现U，这里变成了试U并且发现U，意思变了
C 应该是recover from 不是recover out of
D try for discovery 冗余
E recovering 和 try to do的to do重复

E错在todo 多余

recover from，回收；
try and recover uranium from seawater意思是try uranium and recover uranium，尝试下铀以及回收铀，错误