请教 白勇语法全解中的一道

Once the economic and social usefuless of the motor car wad demonstrated and with its superiority to the horse being proved, much of the early hostility to it in rural regions disappointed..

B 
        and its superiority over the horse had been

C  and its superiority to the horse

D  its superiority over the horse

E with its superiority to the horse having been

白勇语法全解中说选B，我觉得C是对的呀， 白勇觉得and 前后不对称，前面是句子，后面是短语，可是为什么不能看作是省略掉了was呢，两个并列句，可是省略相同的be动词的呀。 B还莫名其妙的使用了过去完成时态，

人非圣贤哦

Once the economic and social usefuless of the motor car was demonstrated and with its superiority to the horse being proved, much of the early hostility to it in rural regions disappointed..

B 
        and its superiority over the horse had been

C  and its superiority to the horse

D  its superiority over the horse

E with its superiority to the horse having been

I think B is the best answer here. first, two things are talked here: (a) usefulness, (b) superiority. When talking about (a), it used a complete sentense: "the .. usefulness was demonstrated", as a consequence, to talk about (b), there must be a complete sentense to keep parallelism; second, "had been" emphasizes that the event happened before the other (usefuless ... demonstrated), which is logic and precisely presents the meaning of the sentense.   So the correct answer is only B.

我不同意rivershining的观点，理由如下：

1、从句子逻辑意思上分析，demonstrate 和 prove 之间没有先后关系（而且这两个词的意思很相近）；

2、从语法的角度来看，prove这个词比较特殊，一般是以主动表被动的形式出现。如：The article has proved most useful. 注意has的后面并没有been出现。关于prove这个词的考点在OG中也出现过几次，LZ可留心注意。

3、从并列和简洁的角度考虑，相同的be助动词须省略。即：prove前省略了was。

4、在GRE和GMAT出现的例句中，也有superiotiy to这样的搭配。

综上所述，这个题目的答案是C.

欢迎继续讨论！