1To do that sort of thing is foolish。I want to see you this evening.All you have to do is to finish it quickly.We found a house to live in.She came here to study English.I warned the patient not to eat cold water after the operation.主语主语宾语宾语表语表语定语定语状语状语宾补宾补一、用法一、用法21.作主语作主语2)2)用用it it作形式主语用不定式作形式主语用不定式 (It+be+adj./n.+to do sth)3)3)例外：例外：It is no good/no use/no help+doing sth.It is no use arguing about it.1)1)常用动名词常用动名词Learning English is very important.Learning English is very important.It is im
