1、概念引入上个单元中，我们已经学习 it 作代词和形式主语、形式宾语的用法，现在将继续学习it 引出强调句的用法及一些与 it 有关的重点句型。先看这些句子：1. There is no doubt that the earth is becoming warmer and that it is human activity that has caused this global warming rather than a random but natural phenomenon.2. It was a scientist called Charles Keeling, who made ac
2、curate measurement of the amount of carbon dioxide in the atmosphere from 1956 to 1997.3. They also agree that itis the burning of more and more fossil fuels that has resulted in this increase in carbon dioxide.4. It was during the 20th century that the temperature of the earth went up about one deg
3、ree Fahrenheit.这些句子都是强调句，中的斜体词部分标识出了句中的强调句结构。用法讲解it 引出的强调句 1强调句的结构：It is / was + 被强调部分（主语，宾语，状语）+ that (who / whom) + 其它部分在强调句型中：1. 被强调部分可以是主语、宾语或状语。2. 引导词一般用 that，如果是人的话，强调主语还可以用 who，强调宾语用 who 和whom 皆可。3. 判断一个句子是否是强调句，我们可以把被强调部分放回到句子中不需要添加任何成分时，句子就是强调句需要注意的是，在考试中，有的题会迷惑大家，许多题以 It is 开头，但是 It is 开头的
4、句子并不全是强调句。那么如何判断呢？看下列例句：1. It was in 2003 that I graduated from the university. 是在 2003 年我们从大学毕业的。此句中有强调句结构“It was. that”，是不是强调句呢？把 in 2003 放回到原来句子中，即：I graduated from the university in 2003.此句非常完整，不缺少成分，是强调句。2. It was not until dark that he realized it was too late to return home.直到天黑他才意识到太晚了，不能回家了
5、。把强调句结构“it was. that”去掉，句子变成：He realized it was too late to return home not until dark.（非正常句子）这是强调句中一个特殊的用法，它的原句应该是：He didnt realize it was too late to return home until dark.注意：not. until 句型中，如果写成强调句的话，要把 not 和 until.部分一起提前。3. Was it in the village which we used to live in that the accident happene
6、d?是在我们过去住的那个村子发生的事故吗？此句是疑问句，较复杂的句子如果不好分析时，可以把原来的疑问句改成陈述句，变化得出：It was in the village which we used to live in that the accident happened.去掉 It was，句子中 that 前是从句“which we used to live in”修饰village，译成“我们过去住过的村子”，是定语从句，which 代替 village 作 live in 的宾语。原句应该是：The accident happened in the village which we us
7、ed to live in.考试时经常把此条件句中 which 和 that 处变成空白处，看看你是否知道填什么词汇。那么分清何处是定语从句，何处是强调句，就很关键了。注意：强调句的一般疑问句形式，把 it is/was 中的 is/was 提前。4. Where was it that the road accident happened yesterday? 昨天是在哪儿发生的交通事故？此句也是疑问句，变成陈述句：It was where that the road accident happened yesterday. （非正常句子）这个强调句的被强调部分，是疑问词，原句是：Where
8、 did the road accident happen yesterday?注意：强调句中如果提问被强调部分，要把疑问词放在句首，后面接一般疑问句语序。5. It is how you behave in difficulties that shows what you are really like.是你在困境中的行为表现出你到底是什么人的。去掉“It is. that”，句子变成：How you behave in difficulties shows what you are really like.是强调句，因为句子很完整，强调的是主语从句。it 引出的强调句 2强调句型的几点注意
9、：1. 句首词用“It”，不能用“This”，“That”等。2. be 动词总用单数形式，即 is 或 was。可以用 might be/ must have been/ cant be 等形式。It might be tomorrow evening that the news will be broadcast.这则消息或许是明天晚上播出。3. 被强调的部分如果是表示“人”的代词，强调主语用主格，强调宾语用宾格。It is him that (who/ whom) I met in the street yesterday. 我昨天在街上遇到的是他。It is I that/ who d
10、idnt realize all my mistakes until you told me yesterday.是我直到昨天你告诉我才意识到我的错误。4. 连接词一般用 that，当强调部分是人时，强调主语也可用 who，强调宾语也可用whom 或 who。当强调部分是时间状语或地点状语时，不能用 when 或 where。It was about 30 years ago that we graduated from university and became teachers.我们是 30 年前从大学毕业成为老师的。It was on Oct. 1st, 1949 that People
11、s Republic of China was founded.中华人民共和国是 1949 年 10 月 1 日成立的。It is in the university where he taught that the research is carrying on.这项研究是在他教过书的大学里进行的。5. 强调句中的主谓一致问题若强调部分是句子的主语，则 that 或 who 引导的句子中的谓语动词应和强调部分保持人称和数的一致，即：若被强调部分是单数，谓语动词用单数形式；若被强调部分是复数，则谓语动词用复数形式。如：It is Mary who often helps me with my
12、English. 是玛丽帮我学英语的。It is the boy students of Class Two who are playing football on the playground.是二班的学生正在操场上踢足球。易与强调句混淆的几个句型1. It is/has been +时间+since . 从以来有since 引导的从句通常是一般过去时，如果 It is 改成 It was，since 从句常用过去完成时。It is years since I enjoyed such a good dinner. 我多年没有享受过这么好的一顿晚饭了。It was five years si
13、nce his father had died. 当时他父亲去世五年了。2. It is +时间+ when . 当的时候，时间是when 引导的是时间状语从句，主句中的 it 指时间，表语由具体的时间充当。It was 10 oclock when we got home last night. 我们昨晚到家时十点了。对比：It was at ten oclock that we got home last night我们昨晚是在十点到家的。此句是强调句，去掉“it was.that”后句子仍然完整合理，注意 that 不能改成when。而上句不是强调句3. It was/ will be
14、. before . 过.就It was not/ will not be. before. 不久就主句中的 it 指时间，表语多是 long, not long , three days , two weeks等表示“一段时间”的词或短语。It was three days before he went to Beijing. 三天后他就去了北京。It will not be long before he finishes his job. 不久他就完成了工作。对比：It was three days ago that he went to Beijing. 他是三天前去的北京。此句是强调句
15、，去掉“it was.that”后句子仍然完整合理。it 的常用句型小结 11. It is clear (obvious/ true/ possible/ certain) that 某事是清楚（明显/真的/可能/肯定）的It was clear that they had no desire for peace. 很清楚他们没有和平的愿望。2. It is important ( necessary, right, strange, natural.) that .与上述句型属同一句型，但由于形容词不同，此句型 that 后的从句中多用虚拟语气（should + 动词原形，should 可
16、省）。It is necessary that he (should) remember these words. 他记住这些词很必要。3. It is said (reported/ learned) that 据说（据报道/据悉）It is believed that proper morning exercises are good for our health.大家都相信适当的晨练对我们的健康有利。4. It is suggested (ordered/ required . ) that . 据建议 (有命令/据要求等)与上一句型属同一句型。主句中的过去分词是表示请求，建议，命令等词
17、时，that 从句要用虚拟语气（should + 动词原形，should 可省）。It is suggested that the meeting (should) be put off. 有人建议延期会议。It was ordered that we (should) arrive there in two hours. 命令要求我们两个小时后到达。5. It is a pity (a shame . ) that .that 从句多用虚拟语气（should + 动词原形，should 可省），表示出乎意料，should 常译为“竟然”。没有这种意义时，则不用虚拟语气。It is a pit
18、y that such a thing (should) happen in your class.这种事竟然发生在你们班上，真是遗憾！ It is a pity that he is ill. 他生病了，真遗憾！it 的常用句型小结 26. It happens that. 碰巧happen 是不及物动词。It (so) happened that he met his teacher in the street. 他碰巧在街上遇到了他的老师。7. It seems/appears that 看来It seems/appears that he will be back in a few d
19、ays. 看来他几天后会回来。8. It looks ( seems ) as if . 看起来好象as if 从句如果与事实不相符合，则用虚拟语气：与现在事实相反，用一般过去时；与过去事实相反，用过去完成时；与将来事实相反，用 would/should+动词原形。It looks as if he is ill. 看起来他病了。（符合事实，不用虚拟语气） It seems as if he were dying. 似乎他垂危了。(不符合事实，用虚拟语气)9. It takes sb. +时间段+ to do sth. 做要花费某人It took thousands of people man
20、y years to build the Great Wall.几千人花了许多年建造了长城。10. It is no good /use doing sth.It is no good learning English without speaking English. 学英语却不说英语没有好处。11. It doesnt matter whether/ if. 不论（是否） 没关系。It doesnt matter whether they are old (or not). 他们年龄大不大没有关系。12. It is time (about/ high) time that . 是（正是）
21、的时侯”。that 从句用虚拟语气(过去时或 should + 动词原形，should 不能省)。It is time that children went/ should go to bed. 13. It is the first ( second ) time that 是第一（二）次that 从句不用虚拟语气，而多用完成时。that 可以省去；it 有时用 this 替换。It /This is the first time I have been here. 这是我第一次去那里。巩固练习. 把下面句子译成英语，注意 it 的用法。1. 过了很久他才回来。_2. 我们两个月后才会再见面
22、。_3. 我离开这所学校已经 20 年了_4. 直到她摘下墨镜我才认出她是个著名影星。_5. 是约 600 年前第一块带有表盘(face)和一个时针（hour hand）的钟表被制造出来的。_6. 昨天是他们打扫的教室。_7. 我是在大街上遇见她的父亲的。_8. 我们弄清楚了我们要在何时何地开会。_9. 据说所有的票都卖完了。_10. 我们真的该采取行动了。_. 从方框中选出能够填入空白处的合适的连接词。1. The weather turned out to be very good, _ was more than we could expect.2. It was not until t
23、en oclock _ we got home last night3. Look at the building. It was the theatre _ Lincoln was murdered.4. Could it be in the restaurant in_ you had dinner with me yesterday_ you left behind your keys and wallet?5. Its years _I painted this beautiful picture.6. It will be years _ I paint this beautiful
24、 picture.7. It was years _ I painted this beautiful picture.8. Its for years _ I have painted this beautiful picture.9. It worried the mother a lot _ her son drove so fast.10. I think it important _ you should attend the conference. 单项选择。1. I have always been honest and straightforward, and it doesn
25、t matter _ I am talking to.Awho is it Bwho it is Cit is who Dit is whom2. It was the ability to do the job _ matters not where you come from or what you are.A. one B. that C. what D. it3. It was after he got what he had desired _he realized it was not so important.A. that B. when C. since D. as4. It
26、 is not how much we do but how much love we put into what we do _ benefits our work most.A. who B. which C. that D. what5. It was April 29, 2011_Prince William and Kate Middleton walked into the palace hall of the wedding ceremony.A. that B. when C. since D. before6. It was along the Mississippi Riv
27、er _ Mark Twain spent much of his childhood.A. how B. which C. that D. where7It was in New Zealand _ Elizabeth first met Mr. Smith.A. that B. how C. which D. when8. It was 4 oclock in the earth morning _ he came to himself in the hospital.A. that B. when C. while D. as9. It is these poisonous produc
28、ts _ can cause the symptoms of the flu, such as headacheand aching muscles.A. who B. that C. how D. what10. It was how the young man had learned five foreign languages _ attracted the audiences interest.A. so that B. that C. what D. in which11. It was only when I reread his poems recently _ I began
29、to appreciate their beauty.A. until B. that C. then D. so12It was because of bad weather _ the football match had to be put off.A. so B. so that C. why D. that13It was where there had been a theatre _ they built a new modern school.A. where B. in which C. that D. so14It was only with the help of the
30、 local people _.A. was the mountain climber rescuedB. that the mountain climber was rescuedC. when the mountain climber was rescuedD. then mountain climber was rescued15It was the bookstore _ I met your brother the other day.Awhere B. that C. on which D. in that16. Its a long time _ I saw you last.
31、Yes, and what a pity! It will be a long time _ we see each other again.A. before, since B. since, before C. when, when D. since, when17. It was _ back home after the experiment.A. not until midnight did he goB. until midnight that he didnt goC. not until midnight that he wentD. until midnight when h
32、e didnt go18. The Foreign Minister said, “_ our hope that the two sides will work towards peace”.A. This is B. There is C. That is D. It is19. I like _ in the autumn when the weather is clear and bright.A. this B. that C. it D. one20. In which play is _ your brother appears?A. that where B. this whe
33、n C. it that D. it where21. It was in the lab _ was taken charge of by Professor Zhang _ they did the experiment.A. where; that B. which; where C. that ; where D. which; that22. If I can help _, I dont like working late into the night.A. so B. that C. it D. them23. As the leader of the village, she
34、made _ her duty to look after all the other peoples affairs in the village.A. this B. that C. one D. it24. Id appreciate _ if you would like to teach me how to use the computer.A. that B. it C. this D. you25. I just wonder _ that makes him so excited.A. why it does B. what he does C. what is it D. w
35、hat it is26. He was nearly drowned once.When was _?_ was in 2010 when he was in middle school.A. that; It B. this; This C. this; It D. that; This27. _in the regulations that you should not tell other people the password of your e-mail account.A. What is required B. What requires C. It is required D.
36、 It requires28. Is _student _was caught smoking in the classroom?A. it that, that B. that it, itC. it it, that D. it which, that29. Where did you get to know her?It was on the farm _ we worked.A. that B. there C. which D. where30. Im sorry youve been waiting so long, but itll still be some time _ Br
37、ian gets back.A. before B. since C. till D. after答案与解析 . 把下面句子译成英语，注意 it 的用法。1. It was long before he came back.2. It will be two months before we meet again.3. It is/ has been twenty years since I left this school.4. It was not until she took off her dark glasses that I realized she was a famous fi
38、lm star./Not until she took off her dark glasses did I realize she was a famous film star. /I didnt realize she was a famous film star until she took off her dark glasses.5. It was about 600 years ago that the first clock with a face and an hour hand was made.6. It was they that /who cleaned the cla
39、ssroom yesterday.7. It was in the street that I met her father.8. We made it clear when and where we were going to have the meeting9. It is said that all the tickets have been sold out.10. Its high time that we took/ should take action.解析：4. 第一个句子是强调句，第二个句子是倒装句，第三个句子是普通句子。. 从方框中选出能够填入空白处的合适的连接词。1. w
40、hich。which 引导非限制性定语从句，代表前面整个句子在从句中作主语。2. that。that 与前面的 it was 一起构成强调句，强调时间状语 until ten oclock。3. where。把 It was 和空格去掉后可以看出句子不完整了，the theatre 前面加上at/in 后句子才合理，所以此句不是强调句。句中 it 指代前句中的 the building，空白处应填 where，代替先行词 theatre 在定语从句中作地点状语。句意：它就是林肯遇害的那家剧院。4. which, that。第一空填 which，引导定语从句，代替先行词 restaurant 在
41、定语从句中作 in 的宾语；第二空填 that，与前面的 Could it be 一起构成强调句。句意：你是在我们昨天吃饭的那家饭店落下了钥匙和钱包吗5. since。表示从 since 从句谓语动作（画这张画）发生以后到现在经过的一段时间，译为“自从以来已多久了”。句意：我几年前画的这张美丽的画。（从画这张画到现在都几年了。）6. before。表示从现在起到 before 从句谓语动作发生要经过的一段时间,译为“多长时间后才会/就会做”。句意：要过几年我才会画这张美丽的画。7. before。表示从过去某一时间到 before 从句谓语动作发生所经过的一段时间,译为“多长时间后才/就做了”
42、句意：几年后我才画了这张美丽的画。8. that。强调句。原句是：I have painted this beautiful picture for years. 句意：这张美丽的画我都画了好几年了。9. that。that 引导主语从句，是真正的主语，it 是形式主语。10. that。that 引导宾语从句，是真正的宾语，因为有宾语补足语 important，用 it作形式宾语，而 that 从句后置。. 单项选择。1. B。考查强调句中强调疑问词时的语序问题(省略了 that)。强调句是 and 连接的并列句的主语从句，被强调部分是疑问词，所以 who 或 whom 放从句句首；而从句的
43、语序用陈述句语序故选 B。2. B。本题强调主语 the ability to do the job，因为把 It wasthat 去掉，句子仍完整。3. A。这是强调时间状语从句 after he got what he had desired 的强调句，故选A。句意：他得到了他想要的东西后才意识到它并不那么重要。4. C。强调句型强调 notbut 连接的并列主语，所以选 C。句意：不是我们做了多少，而是我们倾注于我们做的事的爱有多少最有利于我们的工作。5. B。去掉 it was 和空白处就会发现，此句不是强调句，April 前少 on，所以 it 指代时间，空白处填 when，引导时间
44、状语从句。6. C。对地点状语 along the Mississippi River 进行强调。7. A。强调地点状语。8. B。when 引导时间状语从句，前面的 it 表示时间。句意：他在医院苏醒过来时是早上 4 点钟。9. B。此题强调主语 these poisonous products，把 it isthat 去掉，句意仍完整。句意：是这些有毒产品可以导致诸如头痛和肌肉痛这些流感症状的。10. B。此题强调主语从句 how the young man had learned five foreign languages。把 it wasthat 去掉，句意仍完整。11. B。本句强
45、调时间状语从句 when I reread his poems recently，故选 B。12. D。本句强调原因状语 because of bad weather, 故选 D。在强调原因状语从句时，只能强调由 because 所引导的从句。13. C。本句强调地点状语从句 where there had been a theatre.14. B。本句强调方式状语 only with the help of the local People.15. A。去掉 it was 和空白处后发现少 in，应该填 where 引导定语从句，where 在从句中作地点状语，相当于 in which。句意
46、：它就是我前几天遇到你哥哥的那家书店。16. B. 句型“Its+时间+ since 从句”，表示从从句谓语动作结束开始到现在已经多长时间了。句意是“自从上次见到你到现在已经有很长时间了。”句型“Its+时间段+before 从句”表示“还要才”。17. C。此题强调 until 引导的时间状语 until midnight，要将 not until 放在一起置于 It was/is 之后。在强调句型中不用倒装语序。18. D。It is our hope that,it 是形式主语，代替后置的主语从句。19. C。it 作形式宾语，代替后面的宾语从句。因为 want、like 一类的词不能直接接宾语从句，所以加了形式主语 it。20. C。此句是强调句型的特殊疑问句, 被强调的部分是特殊疑问词 in w
