Question

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

Answer 1

D

解析试题分析：考查特殊不定式：on which 中的which指代sufficient grounds ，to base 中的base 是vt 。后接his argunents 做宾语，这句话结构其实就是 base his arguments on sufficient grounds in favour of the new theory，还有特殊不定式只能用主动形式，eg: I don't know what to do next ? 选D。
考点：考查特殊不定式
点评：不定式的特殊句式可以用来表示表示连动结构。不定式在做定语和做状语时都有其特殊句式，注意这些句式的特点，如： have something to do类：这类结构相当于汉语的连动结构，即"有事要做"，"买东西吃"，"借书看"等。a room in which to live：可以住的房子。