大全925

925. Where once the union had acquiesced to the prejudices of its English-speaking members by supporting the imposition of an alien tax on immigrant workers, after 1897 the United Mine Workers made a determined effort to enlist Italians and Slavs in its ranks.
(A) Where once the union had acquiesced to the prejudices of its English-speaking members by supporting
(B) Where once the union acquiesced to it English-speaking members’ prejudice for the support of
(C) While once the union had acquiesced to the prejudices of its English-speaking members in support of
(D) While once the union acquiesced to its English-speaking members’ prejudice in supporting
(E) While once the union had acquiesced to the prejudices of its English-speaking members in its supporting of

我选了D，答案是A.

有两个疑问，请大家指教：

1。请问where once到底是什么意思？（1） 刘振明的书说：where once 表示 because. 但是这样子放入原文解不通啊。 （2） 还有人说：where 这里指的是 a situation, a position, - where once 所引导的句子所描述的情况，一定会在后面被改变。 我也觉得说的很模糊。

2。而这里为什么一定要用过去完成时呢？虽然这里有after1987，表明acquiesce这个动作是在before1987之前发生的，但是，acquiesce应该是一个瞬间动作，而非持续性动作，这种非持续性动作怎么能用完成时态呢？

I guess you meant to say "past perfect contiuous"?

It can be translated as "there was one time that".

where (longman)

5 used to say that one person, thing, opinion etc is different from another
Where others might have been satisfied, Dawson had higher ambitions.

Where A, B. 放在这里是对比A与B不同吧！

where can be used in the sense of whereas, as can while. However, if you have to choose between while and whereas, you should go with whereas (or where in this case) if while can be ambiguous in the sentence, since it can mean whereas or at the same time that.
So its A.