The professor could hardly find sufficient grounds( ) his arguments in favor of the new theory.

Question

A. to be based on B. to base on C. which to base on
D.on which to base
应该选择哪个？原因是什么？

Answer 1

选D...which指代ground...
前面的介词on必须有，因为这里相当于用了base on the ground这个短语..在定语从句中当用which指代了ground, ground前面的on还是应该存在.但这时候自然要加在 which前面，所以变成了on which to base

Answer 2

B

base on,固定搭配，它的宾语是前面的sufficient grounds

Answer 3

d
定语从句 base on的介词提前
句意 教授找不出支持他新理论的根据