find/think/make/feel/expect/consider/ +名词/形容词+ to do/doing/that
例：
She finds it difficult to finish the job by herself.
I think it important to read English aloud every morning.
She makes it a rule that everyone should make a summary every day.
Lily felt it no use arguing with him about the matter.
、形式宾语:
It作形式宾语可替代非谓语动词与从句
① Vt + it + Oc + O
I feel it hard to finish the work today.
He feels it his duty to help others.
I think it necessary to talk with him.
I think it foolish of you to cheat in exams.
I made it clear that I would never give up.
I took it for granted that I had failed.
adj.只能以不定式作主语，不能以人作主语的，用for adj. 能以不定式和人作主语的，用of
I think it kind of you to help me.
I think it convenientfor you to take exercises in the gym nearby.
② 动词宾补是no use， no good用it
I find swimming relaxing. （不用it）
I find it no use learning like that.
③ Vt + O用it 做形式宾语的情况
I would appreciate it if you give a hand.
I hate it when you talk to me with
