Question

2. It's clever you out the diffi cult math problem.

   A. for;working   B. of;to work

   C. with;work   D. to;to work

Answer 1

2. B

2. B “It is + a心. +of/for+sb. + to do sth. ” 是固定句型;若形容词是描述某人的性格、品 质的词，介词用of;若形容词是描述事物的 词，介词用for。