单选题 The professor could hardly find sufficient grounds ___________ his arguments in favour of the new theory.

A、 to be based on
B、 to base on
C、 which to base on
D、 on which to base

【正确答案】 D

【答案解析】[译文]教授几乎找不到足够的理由作为其论据的基础以支持这种新理论。 [题解]base sth．on…为固定搭配，[D]中的介词on放于指代sufficient grounds的which前，正常语序应是 to base his arguments on sufficient grounds，因此[D]正确。