Once the economic and social usefulness 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 disappeared.

A) and with its superiority to the horse being proved

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

这个题目里面白勇给的答案是B

个人觉得 A D  E的排除是非常简单的

但是BC之间相对比较模糊

B里面为什么要用过去完成时？当然可以理解为这个prove应该发生在hostility disappear之前..那么为什么once从句前面的那个的demonstrate用的是过去时呢？

而C的错误也非常的不明显 最起码我没看出来...

如果同样使用过去时，那么once从句中的两个并列句中后面那个be动词就是可以省略的..

还有什么别的错误让答案明确为B么？

请达人不吝赐教阿....

555我问的问题从来没有人回答...

非常的伤心....