一道语法题求解

yibiaobiao

Once the economic and social usefulness of the motor car was demonstrated {and with its superioty to the horse beinig }proved,much of the early hostility to it in rural regions disappeared.
(A) and with its superioty to the horse beinig
(B) and its superioty over the horse had been
(C) and its superioty to the horse
(D) its superioty over the horse
(E) with its superioty to the horse having been
我个人认为是C，但答案是B。
c选项中，and连接两个并列句子，第二个句子中horse后可以省略was的，不是吗？
B中的had been过去完成时觉得有些牵强。
请指点，谢谢！

yibiaobiao

因为句首的Once存在，所以对had been有戒心

jj449

c选项中，and连接两个并列句子，第二个句子中horse后可以省略was的，不是吗？
有这个说法吗？不能省略吧！and前后结构平行，前面是usefulness was demonstrated，后面是superioty had been proved，这样才平行吧，我觉得
B中的had been过去完成时觉得有些牵强。
强调动作的先后关系。had been动作发生在过去时之前。估计这里的意思是，先证实汽车比马好，再展示汽车的economic and social usefulness