1. it的用法：
（1）指示代词：
A.性别等信息不明确的人
B.指代上文提到过的事物或事情
C.指时间、距离、天气等
（2）作形式主语：
A.代替动词不定式（短语）
B.It is +adj.(for/of sb) to do sth.
C.It takes sb. … to do st
h..
(3)代替动名词（短语）
It is no goo
d/no use/useless doing sth.
(4)代替主语从句
It is +adj.+that从句.
It seems/appears/looks/happens that….
It is a pity/a shame/an honor/a good thing that….
It is said/believed/reported/estimated that….
It is (high/about) time that…. (虚拟)
（5)作形式宾语，代替动名词（短语），不定式（短语）或宾语从句等;
I think/find/believe/consider/feel/make it +adj./n(for/of sb)+to do sth.
I think/fi
nd/believe/consider/feel/make it useless/no use/no good doing sth.
How do you like it if …？ 如果……，你有什么感想？
I like/enjoy/love/prefer//dislike/hate/appreciate it if/when从句.
