约4750字。

　　【牛津译林版】（江苏专用）
　　2012届高三英语一轮复习精品学案：语法部分第3讲代词
　　（要点透析）
　　it的用法
　　一、 指示代词
　　1. 指代上文提过的事物。
　　That vase is valuable. It's more than 200 years old.
　　那个花瓶很珍贵，它有200多年的历史。
　　【辨析】one, ones, it, that, those
　　it特指上文提到的某人和某物；相当于the＋名词。
　　one 指上文提到的某人或某物中任何一个。复数形式是ones。one前面若有形容词修饰，必须用冠词。
　　We've got a big room and two small ones.
　　我们有一间大房间和两间小房间。
　　I have a storybook. It is an amusing one.
　　我有一本故事书，它是有趣的。
　　that和those常有后置定语修饰，有特指意义，that代替不可数名词或单数可数名词，相当于the＋名词；复数名词用those，相当于the ones。
　　The weight of an elephant is much greater than that of a horse.
　　大象比马重得多。
　　【知识运用】
　　①— I can't find my watch.
　　— You haven't found ______？ If you want to buy a new ______， I suggest you buy ______ made in China.
　　②The books on the first shelf are easier than ____________ on the second shelf.
　　③The boy told him his story and also __________ of the girl upstairs.
　　【答案】①it; one; one　②those/the ones　③that/the one
　　2. 指代人时，常指小孩或身份不明的人。
　　— Someone is knocking at the door. Who is it?
　　— It must be Leo. He said he'd come to see me.
　　3. 指代环境或情况。
　　It's too quiet in the room. Everyone just keeps silent.
　　4. 指代时间、季节、天气或距离。
　　It is spring now and it's warm these days.
　　【疑难点击】
　　it指代时间时，有如下句型：
　　(1) It is timefor sth.
　　(for sb.)to do sth.
　　that－从句( should do/ did，必须用虚
　　拟语气)
　　It's time for lunch.