求助prep一道语法题2

cate88cn

The federal rules aimed at protecting human subjects of medical experiments were established to ensure that patients must be warned of potential risks and an independent panel would evaluate the experiment before it was conducted.

(a) ....
(b) must be warned of potential risks and that an independent panel
(c) are warned about potential risks and that an independent panel
(d) will be warned about potential risks and an independent panel would
(e) would be warned of potential risks and that an independent panel would
答案选E,不是ensure后面应用should虚拟，接动词原形吗

lwtianliang

首先是划线前ensure that ...所以后面要用 and that否则会引起歧义。剩下 BCE，BC后面没有would而E有would，而句子后面是before it was conducted，所以必须要用would， 所以选E

MollyDong

补充楼上：that不能省略所以剩下bce这个没问题，后面应该从and前后严格对称来解决。
B：前面是must be done，后面却省略了should，不对称；而且must在语意上和ensure重复，自习体会一下？
C：同理，前面是正常句子，be done结构（一般现在时，没有任何情态动词或者虚拟的征兆），后面却省略了should
E：严格对称。而且ensure没有必须要求虚拟省略should吧。。。

yangyx8833

thanks

fight2015

ensure that 必须虚拟么？