语法专题十：it的用法1.指代事物、动物、婴儿或未知的人。

2.指天气、时间、距离、自然现象、环境等。

3.代替不定式，作形式主语或形式宾语(常与feel, consider, find, believe, make, take,imagine, think, suppose, regard等连用)。

4.代替动名词，作形式主语或形式宾语：It is no good / no use / useless / dangerous + doingI think it no good / no use / useless / dangerous + doingI think it no use complaining about their prejudice.5.代替主语从句、宾语从句，作形式主语或形式宾语：It seems / appears / happens / turns out / proves + that…It is certain / likely / possible / probable + that…We have made it clear that she has nothing to do with the case.6.用于强调句：It is / was … that / who…A student witnessed the car accident at the turning last night.(1 ) ( 2 ) ( 3 ) ( 4 )(1) _________________________________________________________.(2) _________________________________________________________.(3) _________________________________________________________.(4) _________________________________________________________.It is not until +被强调的部分+ that…I didn’t realize she was a famous film star until she took off her dark glasses.________________________________________________________________.7. 其他重要句型：It is important (necessary, right, strange, natural) that…（should+动词原形）It is said (reported, learned…) that…It is suggested (ordered…) that…（should）+动词原形It is a pity (a sham) that …（should）+动词原形It happens (seems, looks, appears ) that...It occurs to sb. to do / that…：使某人想起……It is/ has been +一段时间+ since ...+过去时It will be +一段时间+ before ...It looks ( seems ) as if …It is no wonder…：难怪When it comes to…：当谈到……It comes about that…：发生8. appreciate, love, like, hate, see to(负责，注意) + it + 从句巩固练习：1. It took us over an hour ______ along the street.A. walkB. to walkC. walkingD. walked2. I think it a great honour ______to visit your country.A. to inviteB. invitingC. having invitedD. to be invited3. Many people now make ______a rule to buy cards for their friends before Christmas.A. themselvesB. itC. thatD. this4.______is very clear to everyone that he's round and tall like a tree.A. ThisB. WhatC. ThatD. It5. ---It is raining cats and dogs.---______ .A. So it isB. So is itC. Neither it isD. Neither is it6. It's no use ______over spilt milk.A. cryB. cryingC. that you cryD. for you to cry7. It is important ______ their offer.A. rejectB. rejectsC. to rejectD. rejecting8. Has ______been decided when we are to hold the sports-meeting?A. thatB. thisC. itD. what9. ---Did Li Lei call me while I was out?---Yes, it was ______ that called you.A. h imB. heC. whoD. whom10. I don't know ______makes her afraid of having her business discussed.A. what it is about Mary thatB. that is it abut Mary whatC. what is it about Mary thatD. that is about Mary what11. It was with great joy ______ he received the news that his long lost son would return home.A. asB. thatC. soD. for12. I don't think ______difficult for a student to master a foreign language within five years.A. thatB. itC. tooD. very13. It's the second time you ______ late this week.A. arrive B .arrived C. have arrived D. had arrived14. It will not be ______we meet again.A. long beforeB. before longC. soon afterD. shortly after15. It's demanded that we ______there on foot.A. not to goB. don't goC. not goD. won't go16. It was not until 1936 ______ basketball became a regular part of the Olympic Games.A. thatB. whenC. whichD. then17. ______ you met the Englishman?A. Where it was thatB. Who it was thatC. Where was it thatD. Where was that18. ______ certain that his invention will lead to the development of production.A. That'sB. This isC. It'sD. What's19. Tom's mother kept telling him that he should work harder, but ______didn't help.A. heB. whichC. sheD. it20. It is important that she ______with Mr. Williams immediately.A. speakB. spokeC. will speakD. to speak21. ______that there’s another good harvest this year.A. It saysB. It is saidC. It was saidD. He was said22. I really appreciate ______ if you can lend your computer.A. thatB. whatC. itD. which23. I didn’t ______ her ______ for help.A. occur; to askB. occur to; to askC. occur to; askingD. happen to; that to ask。