灌云县四队中学学案巩固案Studying aims: To learn how to use it as an empty subject and object.Self education (自主学习)Revision: What is the function of“it” in the sentences below ?1. It’s a book. ( )2. It’s ten o’clock. ( )3. It’s raining outside. ( )4. It’s a long way to the museum. ( )Team work (合作探究):Task 1 形式主语 it1) 替代不定式短语作主语。如：It was his duty to attend to the matter. 处理这件事是他的责任。_______ is impossible ________________________. 准时完成工作是不可能的。2) 替代动名词作主语。如：It is useless crying over the spilt milk. 覆水难收。_______ no use __________________________________. 再说这件事没用。3) 由于主语从句位于句首，句子常显得笨重，因此常把它移至句子后部，句首用引导词 it 来作形式主语，替代主语从句。如：It is a pity that she has made such a foolish mistake. 他犯了如此愚蠢的错误，真遗憾。________ is reported ___________________________________________________.据报道，三个人在这次交通事故中遇难。Task 2 用作形式主语 it 的重要句型 ◆ It 替代动词不定式作主语的常见句型：① It + be + adj. + for (of) sb to do sth 某人做某事……It is hard for him to make up his mind. 他很难下定决心。It was foolish of her to say such a thing. 她说那样的话，真是太蠢了。【想一想】如何选择上述句型中的介词 of 和 for ?② It takes sb + 时间段 + to do sth. 某人做某事花了……时间It takes years to master a new language. 要花多年的时间才能掌握一门新的语言。______________________________________我写这封信花了一个小时。It 替代动名词作主语的常见句型：It’s no good/use doing…It’s useless doing…It’s (well) worth/worthwhile doing…◆ It 替代主语从句的常见句型：① It + be +adj. +that 从句It is clear that he mistook me for my younger sister.② It + be + 过去分词 + that …. = sb./sth. + be+过去分词+to do It is believed that China has become one of the str...
