帮我看一个非谓语动词选择题
问题描述：
帮我看一个非谓语动词选择题
6.The professor could hardly find sufficient grounds _____ his arguments in favor of the new theory.
A.to be based on B.to base on C.which to base on
D.on which to base
D 为什么不能A呢?
答
6. The professor could hardly find sufficient grounds _____ his arguments in favor of the new theory. A. to be based onB. to base onC. which to base onD. on which to base答案：D为什么...