18.   The National Labor Relations Act expressly forbids unions from engaging in secondary boycotts against companies not directly involved in a labor dispute.

(A) unions from engaging in

(B) the engagement by unions of

(C) unions to engage in

(D) unions from becoming engaged with（C）

(E) that unions engage upon

找了半天，没有找到讨论的链接。我发一下题目，不明白的是A和C有什么区别 

NN请指点一下，太谢谢啦！！

idioms

forbid somebody to do something

prohibit somebody from doing something

谢谢回复。我知道prohibit不可以用不定式，但是forbid可以用from doing。

我查longman，里面也有forbid sb. from doing sth.的用法 。复制如下。

forbid: to tell someone that they are not allowed to do something, or that something is not allowed
ￚopposite permit
forbid somebody to do something
He was forbidden to leave the house, as a punishment.
forbid somebody from doing something
Women are forbidden from going out without a veil.

这个怎么理解呢？

谢谢 ^_^

OG-100:

100. Wisconsin, Illinois, Florida, and Minnesota have begun to enforce statewide bans prohibiting landfills to accept leaves, brush, and grass clippings.

(A)  prohibiting landfills to accept leaves, brush, and grass clippings

(B)  prohibiting that landfills accept leaves, brush, and grass clippings

(C)  prohibiting landfills from accepting leaves, brush, and grass clippings

(D)  that leaves, brush, and grass clippings cannot be accepted in landfills

(E)   that landfills cannot accept leaves, brush, and grass clippings

Choice C is the best answer. Either of the following constructions would be idiomatic here: x forbids y to do z or x prohibits y from doing z. Choices A and B violate idiom; \ D and E introduce constructions that, in context, are faulty. First of all, both bans that x cannot be done and bans that y cannot do x are unidiomatic formulations. Secondly, the negative cannot after bans is illogical.

只能说OG有这样的偏好了