第三部分：语法---It 的用法 【学习目标】知识目标：学习代词 it 的各种用法。能力目标：能熟练运用到各种场合，能够解答与之相关的习题，学会使用 it 有关的高级句型尤其是强调句型、it 作形式主语。【课前自学】代词的用法：一、作人称代词1、it 代替前面（或后面）的单数名词或分句等所表示的事物。e.g. You cannot eat your cake but have it.（it 代替前面的_________）Although we cannot see it, there is air all around us. （it 代替后面的_________）They say he has left town, but I don’t believe it. （it 代替前面_________）2、代替有生命但不能或不必分阴阳性的东西（包括婴儿）。e.g. Yesterday we saw a big tree. It was fully twenty metres high. （it 代替前面的_______）The baby cried because it was hungry. （it 代替前面的_________）3、在某些习惯说法中，可以代替人。e.g. ---- Someone is knocking at the door, Peter.---- Who is _________?---- _________ me.---- Who are singing?---- It is the children.---- The light is still on in the lab. It must be the third-year students doing the experiment.4、it 与 one 的区别：这两个词都可以代表前面说过的名词，但 it 用于同名同物的场合；one 则用于同名异物的场合。e.g. ---- Do you still have the bicycle?---- No, I have sold _________---- Is this knife yours?---- No. It is Xiao Zhang’s. Mine is ____ _____ on the desk.5、it 与 that 的区别：两词都可代替某一特定名词，但 that 指同一类，并非同一个。用心 爱心 专心e.g. The climate of South China is mild（温和的）; I like______very much.（_________指 the climate of South China）The climate of South China is much better than_________of Japan.（_________指 the climate）二、作无人称代词it 作无人称代词时，除了句中找不到它所代表的词语外，另一个特点是它后面的内容都是表示天气、时间、距离、度量衡及情况等。It is fine (rainy, windy, etc.).It is noon.It is a half hour’s walk to the factory.It is eighteen square metres in area.What does it ma...
