高中英语 语法精讲（Unit 20Archaeology）大纲人教版第二册语法精讲 IT的用法1.用作人称代词，代替前文提到过的事物 The frog is not a warm-blooded animal.It is cold-blooded one.2.用以代替指示代词this,thatWhat is this?It is a flag. It is hers.3.起指示代词的作用，指一个人或事物Who is knocking at the door?It is me.Who is making such a noise?It must be the children 4.指环境情况等It was very quiet(noisy)at the moment.5.指时间、季节等What time is it?It is eight oclock.It often rains in summer.6.指距离It is five kilometers from the office to my home.7.形式主语it的用法(1)It is+clear+that(2)It is+cruel(kind,brave,nice,rude,wise,stupid,clever,foolish,polite)+of sb.+to do sth. (3)It is important(necessary,possible,impossible,easy,difficult,hard)+for sb.+to do sth.It is foolish of you to waste money.It is silly of him to say that.介词for和of的区别依前面的那个形容词而定。如果那个形容词指的是一种行为的性质，就要用for;如果那个形容词指的是行为的性质，同时又指行为的人，就用of。换句话说，单说行为的用for,如necessary一词，仅指“行为”，而无法指“行为者”；而说及行为者的用of，如kind一词，可以说“你的行为是亲切的”，也可以认为作为“行为者的你是亲切的”。 It is rude for the young to make fun of their elders.It was very kind of your uncle to give us a lift in his car.It seems that he is ill.It happened that he wasnt at home.8.形式宾语it的用法I+believe(make,consider,regard,suppose,feel,think,find,)+it+宾语补足语+to do如：I think it important to work hard every day。9.用于强调结构要强调句子的某一部分（通常是主语、状语、宾语），可以把it当作先行词。这种句子的结构是“It is(was)+被强调部分+that(who,whom)+句子的其余部分。”如果强调的部分是人，可用who,whom代替that。例如：It is Prof.Lin who teaches us English.(强调主语)It is English that Prof.Lin teaches us.(强调宾语) It was in Shanghai that I saw the film.(强调状语)It was in 1975 that I worked in a factory.(强调状语)考题再现【考例1】(2006全国高考,26) If I can help_,I dont like working late into the night. A.so B.that C.it D.them解析:if I can help it意为“如果我有办法”，表示有办法做某事，或有办法控制某个局面。所提供的情景“I dont like working late into the night”说明如果有办法，不喜欢工作到深夜。so意为“这样”，常用于省略句中，代替上文中的动作。that用于代替上文的内容。答案：C 【考例2】(2006山东高考，24) Id appreciate _if you would like to teach me how to use the computer.A.that B.it C.this D.you解析:it指代用来泛泛地指某事，可用于如I like it, I appreciate it等类似的句子，表示喜欢和赞赏某事，it和that均可指代前面提到的名词或事，it是人称代词，可指代同名同物，指代有不定冠词的或有其他限定词的单数可数名词，也可指代一件具体的事；that是指示代词，常指代有定冠词的单数可数名词和不可数名词，也可指代刚提到的一件具体事。答案:B【考例3】(2006安徽高考，34)Catherine bought a postcard of the place she was visiting,addressed_to_and then posted it at the nearby post office.A.it;her B.it;herself C.herself;her D.herself;herself解析:address sth. to sb.“把（话）讲给，把（信）写给”。 答案：B【考例4】(2006江苏扬州一模)_in the school rules that boy students should not wear long hair.A.What is required B.What requiresC.It is required D.It requires解析:考查名词性从句。it是形式主语，that引导的从句是真正的主语。答案：C【考例5】(2005山西太原一模) We have made_a rule to practise oral English whenever and wherever_possible.A.it;its B.it;it C.that;it D.it;/解析:考查代词it的基本用法。it可作形式主语和形式宾语，无意义，真正的主语和宾语后置。make it a rule to do即为该用法，第二空为省略句，在时间和条件状语从句中，从句的主语是it,谓语是be动词，此时it is/was可一同省略。答案：D【考例6】(2006黄冈一模) He looks unhappy.Yes,but he cant say what it is_is bothering him.A.as B.that C.what D.which解析:考查强调句型。.“what it is that is bothering him”是强调句型。答案：B3 / 3