Someone is ringing the doorbell. Go and see who it is. It’s John on the phone. 2. 用作非人称代词，指时间、天气、距离或自
然现象等。如： It is only half an hour’s walk to the hospital.
It’s about two kilometers from here to the station. It is raining heavily outside. 二、it作引导词 1. it作形式主语的常用句型 ★ “It + be +名词+主语从句”中从句谓语常用“（should +）动词原形”。常用于本句型的主要有a pity, a shame, no wonder, no accident等。如： It is a great pity that he should be so greedy.
It is a shame that he should attempt to injure the reputation of an honest man.
It was no accident that such a book should appear in the 18th century. ★ “It + be +形容词+主语从句”中从句谓语常用“（should +）动词原形（或完成时）”。常用于本句型的形容词主要有impossible, strange,
surprising等。如： It is impossible that it should be a mere coincidence.
It’s strange that she should have been arrested for stealing.
It was surprising that he should have finished writing a novel in only twenty days.
★ “It +动词（+宾语或状语）+主语从句”。常用于本句型的动词主要有please, happen等。如： It pleased me very much that he succeeded.
It pleases me that he should want to talk with me.
It so happened that he had just left for Tianjin.
★ “It +动词的被动语态+主语从句”。常用于本句型的动词主要有accept, admit, allow, announce等。如： It’s accepted that the universe is endless.
It is generally admitted that he is a trustworthy person.
It was announced that all prisoners would be set free.
It was announced that the Prime Minister would speak on television that evening.
2. it作形式宾语 ★根据句子结构的需要，人们常用it作形式宾语，而将真正的宾语放在宾语补足语后。常用于这种句型的动词有believe, bring, consider, declare, feel, find, make, prove, think等。如： I find it amazing that anyone would want to listen to that music. I don’t think it possible to master a foreign language within 3 months.
I found it worthwhile reading this book. ★it作形式宾语的常用句型： 1）动词+ it + if / when从句 当enjoy, like, dislike, love, hate, prefer, appreciate等动词后需要接一个if或when引导的从句时，需要在动词后接it作形式宾语。如： She won’t like it if you arrive late.
He hates it when people use his bike.
I’d prefer it if I didn’t have to do so much work.
I would appreciate it very much if you would help me with it.
2）动词+介词+ it + that从句 能用于此句型的主要有：depend on, answer for, see to。如： You may depend on it that he will turn up in time.
I can’t answer for it that the boy is honest.
I’ll see to it that all these letters will be sent to the post before twelve. 三、it用于强调句型中 强调句型可以对句中除谓语动词以外的成分加以强调。 四、it用在一些固定表达中 As someone puts it, ... 像某人所说的那样 Please see to it that ... 请务必…… When it comes to ... 当提到……时 It looks / seems as if ... 看起来好像…… It’s time for sth. 该做某事了 It’s time (for sb.) to do sth. （某人）该干某事了 It is (high) time that ... （早就）该…… It’s first / second / third / ... time + that ... 这是某人第几次干某事（从句谓语用现在完成时） It is / has been +一段时间+ since ... 自从……已经……； It wasn’t / won’t be long before ... 没过多久就 / 很快…… It’s + 时间段 + before ... 过……时间才…… 五、it与one的区别 两者均可代替前面提到的事物，区别是：it指的是与前面已提到的事物为同一物，此时的it等于“the +名词”；而one 指的是与前面已提到的事物为同一类物，此时的one等于“a +名词”。如： I have a dictionary but I’ve lent it to Mary.
I haven’t a dictionary; can you lend me one? I. 选用括号内合适的单词填空。 1. It was only after she had begun to carry out
the task ________ (that, when) Mary realized
it was extremely difficult to complete. 2. ___ (It, As) is our belief that we can make a
good life if we work hard. 3. ___ (It, What) is suggested that parents
should pay more attention to their children’s
inner world. that It
It
4. As a matter of fact, _____ (that, it) is not
failure itself, but what we think of failure and
what we do afterwards that counts.
5. —Do you still drive your Ford car?
—No, I sold ____ (it, that) two years ago. 6. You must keep ____ (it, what) in mind
that you can never be too careful when
proofreading the newspaper. 7. Will ____ (that, it) be convenient for you
to start work tomorrow? it it it it 8. ______ (There, It) is no doubt that the
visiting team, which has better players, will
win the match. 9. —I don’t think I can work out the maths
problem. It’s too difficult.
—Think it over, and perhaps you will make
________ (it, that). There
it II. 用there或it的正确形式填空。 1. During my stay there I made ____ a rule not
to eat fatty foods. 2. I’d appreciate ____ if you could help
me find out the reason why the computer
doesn’t work.
3. I kept telling Mary not to stay up too late
any more, but ____ didn’t help.
4. _____ is an urgent need for qualified
teachers. 5. I like ____ when I am with people like
Mr. Ma, who is always willing to help others.
it it it There
it 6. —Who is making loud noises outside the
window?
—______ is Tom, my neighbour’s son. 7. ________ was no point in staying any longer. 8. I’m as good a cook as she is except when
_____ comes to making pizza. 9. I have no idea who ____ was that taught
me the trick, which helped me to solve the
problem. 10. ________ is a hard job for such a little boy
to carry the heavy box upstairs. Let’s
give him a hand. It There
it it It