it is用法
It is ... that/since/before等句型归纳
????1. 为了突出或强调句中的某一成分以加强语气,英语中通常用“It is +被强调成分+ that/who”结构，这一结构叫作强调结构。该结构中的It ?是无人崐????称主语,没有词汇意义,仅起到改变句子结构,使某一成分受到强调的作用。如被崐????强调的是物，
用that;如被强调的是人,用who,也可用that。
????强调结构中被强调的成分通常是句中的主语、宾语、地点状语或时间状语。例如下面一句, 我们可分别对其不同成分进行强调：
John wore a white suit at the dance last night.
1.It was John that/who wore a white suit at the dance last night.（强调主语）
2. It was a white suit that John wore at the dance last night. (强调宾语）
3. It was at the dance that John wore a white suit last night. (强调地点状语）
4. It was last night that John wore a white suit at the dance.（强调时间状语）????强调结构亦可用来强调某些状语从句：
It was because he was ill that he didn't come to school yesterday.（强调because 引导的原因状语从句）
It was only when the war was over in 1949 that he was able to get back home.
(强调when 引导的时间状语从句）
It was not until his father came back that he went to bed. (强调until引导的时间状语从句）
????现谈谈强调结构中值得注意的几个问题：
????一. 强调结构中的时态问题
????如果被强调的成分，原句谓语动词是一般现在时或一般将来时，强调结构用It
is...that/who; 如果原句的谓语动词是过去时态，则用? It was...that/who; 有时还可
用be 的其它形式。例如：
It is the people who/that are really powerful.
It was in the street that I met your brother yesterday.
It must be your mother who you are thinking of.
????二. 强调结构中代词的格和谓语人称与数的问题
????如果被强调的部分是原句的主语, that/who 后面的谓语在人称和数上均应与原句主语一致, 不与it 一致。例如：
It is you that/who are to blame.
It is I that am mistaken.
????一般说来, 强调主格人称代词就用主格, 强调宾格人称代词就用宾格, 但有时被强调的格与原句中的格不一致。例如：
I met her in the street this morning.
It was her that I met in the street this morning.
her 在原句中是met 的宾语, 所以被强调时仍用宾格形式, 但也可用主格
she 替换her。例如：
It was she that I met in the street this morning.
????这时, 说话者遵循传统语法, 认为动词be 后面的代词用主格,?而不管这个代词在原句中究竟是主格还是宾格。
????强调主格时也有两种情况, 尤其是在非正式的口语中常用宾格代替主格。例如：
They saved the drowning girl.
It was they who saved the drowning girl.
It was them who saved the drowning girl.
????三. 强调结构中的一般疑问句和特殊疑问句问题
????一般疑问句只需将"It" 与"is/was" 交换位置即可。例如：
Was it you that broke the window?
Was it here that you met him?
????如强调疑问句, 需将疑问词置于句首：
Who was it that called him "comrade"?
What is it that you are going to do?
When is it that they will leave?
????四. 强调结构中的that/who 在口语中常可省略：
It was you I thought of all the time.
It is here he must come.
It was John I gave the book to.
Was it in Chengdu you first met him?
What is it you want me to do?
五. 注意固定言语中的意思：
It is a wise father that knows his own child.聪明的父亲往往也不了解自己的儿子。
It is a long lane that has no turning. 胡同不管怎样长，总是要拐弯的。（天无绝人之路）It is a long night that never finds the day. 漫漫长夜，总有拂晓时。
It is a silly fish that is caught twice. 任何鱼都不会愚蠢到上两次钩。
2．It is (high) time that…
该句型中的that可省略，从句谓语通常是动词的过去式，也可用should + 动词原形。相当于It is time for sb. to do sth.例如：
It is time that we went to school.
It is time I ought to leave now.
It’s high time that we should put an end to the controver sy.
3．It is + n.+ that…
该句型为主语从句。It为形式主语，真正的主语是that引导的从句。例如：
It is a pity that you didn’t see the film yesterday.
It is a wonder that he refused such a good offer.
It is common knowledge that the traffic situation there is deplorable.
用于该句型的名词常见有：common knowledge, common sense, a good thing, an honor, a mercy, a pity, a pleasure, a shame, a surprise, a wonder等。
4．It is + adj.+ that…
该句型为主语从句。It为形式主语，真正的主语也是由that引导的从句。例如：
It is certain that we shall be late.
It’s strange that he didn’t come yesterday.
Isn’t it strange that the lazy boy (should) pass the exam.
能用于该句型的形容词常见的有：certain, clear, curious, disappointing, dreadful, fit, fortunate, frightening, funny, good, important, lucky, natural, necessary, obvious, peculiar, pleasing, possible, probable, proper, right, sad, surprising, remarkable, unfortunate, unimportant, unnecessary, unusual, useless, well, wonderful, wrong, true等。that从句可用陈述语气，也可用should + 动词原型的虚拟语气形式。用陈述语气表示客观事实；用虚拟语气表示惊讶、喜悦、遗憾、失望等感情色彩或表示要求、建议、命令、愿望等。
5．It is + p.p. + that…
该句型为主语从句。It为形式主语，真正的主语是that引导的从句。例如：
It was said that Mr. White had been writing a new TV play.
It is reported that the sports meet has been put off.
It has not been decided that when and where we ill hold the meeting.
能用于该句型的过去分词常见的有：admitted, announced, believed, decided, demanded, disclosed, expected, found, hoped, reported, requested, said, seen, suggested, thought, told, unknown,等。
6．It is…before…
该句型的is后可接long或一段时间。肯定句译为“过多久…才…”；否定句译为“没多久…就…”。例如：
It was a long time before I got to sleep again.
It will be hours before he arrives here.
It was not long before he left his home town.
It will be five years before we meet again.
It wasn’t long before he told us about this affair.
It was evening before we reached the little town.
7．It is … since…
该句型表达“从……以来已经多久了”的意思。这一结构多用一般过去时，表示从过去某一时刻起到说话这一时刻止的这段时间的总和。时间的起点，无论是那种动词，一律从since从句中的谓语动词表示的动作的完成的那一刻算起。例如：
It is 15 years since the war ended.
It is just a week since we arrived here.
It is ten years since he left his home town.
It must be almost 5 years since we last met.
从句中可用现在完成时。例如：
It is three years since I’ve seen him. = It is three years since I saw him.
since从句如为延续性动词，用一般过去时，表示“动作的结束”。例如：
It’s years since I enjoyed myself so much.
It is four years since she was a nurse.
How long is it since you were in London.
8．It is … when
该句型中when引导的是时间状语从句，其前面是表示时间的词作表语，强调句型中that 前面被前调的是状语。例如：
It was ten o’clock in the evening when he came back.
It is twelve o'clock at midnight when they arrived at a lovely village.
It was 2005 when he left his home town.
练习：
1.----He was nearly drowned once.
----When was____?
----____ was in 1998 when he was in middle school.
A. that, it
B. this, This
C. this, It
D. that, This
2.The Foreign Minister said “____ our hope that the two sides work towards peace.”
A. This
B. There is
C. That is
D. It is
3. It is almost five years ____ we saw each other last time.
A. before
B. since
C. after
D. when
4. ____ in the regulations that you should not tell other people the password of tour E-mail
account.
A. What is required
B. What requires
C. It is required
D. It requires
5. It is pretty well understood ____ controls the flow of carbon dioxide in and out the
atmosphere today.
A. that
B. when
C. what
D. how
6. It is difficul t for us to learn a lesson in life ____ we’ve actually had that lesson.
A. until
B. after
C. since
D. when
7.I have always been honest and straightforward, and it doesn’t matter ____ I’m talking to.
A. who is it
B. who it is
C. it is who
D. it is whom
8. It is none of your business ____ other people think about you. Believe yourself.
A. how
B. what
C. which
D. when
9. ----Did Jack come back early last night?
----Yes. It was not yet eight o’clock ____ he arrived home.
A. before
B. when
C. that until
10. Scientists say it may be five or six years ____ it is possible to test this medicine on human
patients.
A. since
B. after
C. before
D. when
11. He was told that it would be at least three more months ____ he could recover and return to
work.
A. when
B. before
C. since
D. that
12. It was evening ____ we reached the little town of Winchester.
A. that
B. until
C. since
D. before
13. The field research will take Joan and Paul about five months; it will be a long time ____ we
meet them again.
A. after
B. before
C. since
D. when
14. Great changes have taken place in that school. It is no longer ____ it was 20 years ago, ___,
it was so poorly equipped.
A. what, when
B. that, which
C. what, which
D. which, that
15. That was really a splendid evening. It is years ____ I enjoyed myself so much.
A. when
B. that
C. since
D. since
16. It was some time ____ we realized the truth.
A. when
B. until
C. since
D. before
17. ____ has been announced, we shall have our final exam next month.
A. That
B. As
C. It
D. What
18.I’m afraid I’m not fit for the job, as it is one ____ requires lots of patience.
A. who
B. that
C. what
D. where
19. It is high time ____ I went back home.
A. on which
B. which
C. when
D. X
20. ----Was it midnight ____ you arrived home by taxi?
----I’m afraid so.
A. that
B. at which
C. the time
D. when
21. It was several years ____ I finally realized ____ you enjoyed and built on those abilities.
A. when, that
B. that, when
C. before, that
D. until, why
22. It is not yet pretty well understand ____ made the rainforest disappear year by year.
A. what
B. which
C. that
D. how
23. ____ sometimes keeps her awake at night ____ Tom is getting more and more quiet at home.
A. That, which
B. It, that
C. Whether, what
D. What, that
24. ____ worries me the way he keeps changing his mind.
A. This
B. That
C. What
D. It
25. It was in this park ____ they met for the first time ____ the old couple told us their
unforgettable experience.
A. where, that
B. that, that
C. where, when
D. that, when
26. Why! I have nothing to confess. ____ you want me to try.
A. What is it that
B. What it is that
C. How is it that
D. How it is that
27. It was drinking ____ cost the man a lot of money ____ he ought to have spent on his family.
A. that, that
B. what, what
C. that, what
D. what, that
28. It is no wonder ____ he has succeeded.
A. when
B. what
C. which
D. that
29. ----Where did you meet Joan?
----It was in the hotel ___she stayed.
A. that
B. where
C. which
D. there
30.Is it good to look up every new word ____ I came across it in reading?
A. when
B. before
C. that
D. where
1------5 A D B C C 6-----10 A B B B C
11---15 B C B A D 16----20 D B B D D
21---25 B A B D A 26----30 A A D B A
2011届高考英语一轮复习讲解：it的用法
2011届高考英语一轮复习讲解：it的用法【知识要点】 It的用法 （一）作人称代词 1、it代替前面（或后面）的单数名词或分句等所表示的事物。 e.g. You cannot eat your cake but have it.（it代替前面的cake） Although we cannot see it, there is air all around us. （it代替后面的air） They say he has left town, but I don’t believe it.（it代替前面They…town分句中的情况） 2、代替有生命但不能或不必分阴阳性的东西（包括婴儿）。 e.g. Yesterday we saw a big tree. It was fully twenty metres high. （it代替前面的tree） The baby cried because it was hungry. （it代替前面的baby） 3、在某些习惯说法中，可以代替人。 e.g. ---- Someone is knocking at the door, Peter. ---- Who is it? ---- It’s me. ---- Who are singing? ---- It is the children. ---- The light is still on in the lab. It must be the third-year students doing the experiment. 4、it与one的区别：这两个词都可以代表前面说过的名词，但it用于同名同物的场合；one则用于同名异物的场合。 e.g. ---- Do you still have the bicycle? ---- No, I have sold it. ---- Is this knife yours? ---- No. It is Xiao Zhang’s. Mine is the one on the desk. 5、it与that的区别：两词都可代替某一特定名词，但that指同一类，并非同一个。 e.g. The climate of South China is mild（温和的）; I like it very much.（it指the climate of South China） The climate of South China is much better than that of Japan.（that指the climate）（二）作无人称代词 it作无人称代词时，除了句中找不到它所代表的词语外，另一个特点是它后面的内容都是表示天气、时间、距离、度量衡及情况等。 It is fine (rainy, windy, etc.). It is noon. It is a half hour’s walk to the f actory. It is eighteen square metres in area. What does it matter? （三）作强调词，构成强调结构
it的用法归纳
?Never be afraid of grammar ?Collect some examples; ?Watch them very carefully; ?Find out something in common; ?Try to use the rules ---- practise. it用法完全归纳 一、it 作人称代词的用法 1.指事物 作为人称代词，it 可以除人以外的一切事物或动物。如： I dropped my watch and it broke. 我把手表掉在地上摔坏了。 It’s hard work, but I enjoy it. 工作很辛苦，可是我乐意干。 “Where is the dog?”“It’s in the bedroom. ”“狗在哪?”“在卧室里”。 2.指人 it 指人主要用于指不性别不明的婴儿或用于确认某人的身份。如： Is it a boy or a girl? 是男孩还是女孩? There is a knock on the door. It must be the postman. 有人在敲门，一定是邮递员。 【说明】在答语中，常用来指本人，如说It’s me。
3.代替某些代词 代词it 还可用于代替指示代词this, that 以及复合不定代词something, anything, nothing等。如： “What’s this?”“It’s a new machine. ”“这是什么?”“是一种新机器”。 Nothing is wrong, is it? 没出什么问题，是吗? 二、it 作非人称代词的用法 1.基本用法 it 作非人称代词的用法，主要用于指时间、距离、价值、天气、气候及温度等自然现象。如： It’s too late to go there now. 现在去那儿已经太迟了。 It rained all day yesterday. 昨天下了一天的雨。 It can get very hot here. 这里有时会很热。 2.用于某些句型 It’s time for sth. 该做某事了。 It’s time to do sth. 该做某事的时候了。 It’s time for sb to do sth. 某人该干某事了。 It’s (about / high) time + that-从句. 某人该做某事了。(从句谓语用过去式，有时也用“should+动词原形”) It’s first (second) time + that-从句. 某人第几次干某事。(从句谓语用现在完成时)
it的用法及句型总结
It的用法 一、Tell the functions for “it” in each sentence: 1、---What’s the weather together ---It is fine. 2. It is hard to communicate with him. 3. I find it hard to communicate with him. 4. It is Li that who cleaned the classroom. 5. It is a book. 二、It 用法归纳 1，指代it （1）.用作人称代词：指代物、整个句子 （2）用作非人称代词 2，形式it：（1）作形式主语（2）作形式宾语 3，强调it 4，特殊句型 5.在答语中指代this/that： 1).--- Whose book is that ---It’s mine. 三、特别注意： it, one和that作替代词的用法及区别 1. it代替前面提到的同一事物,该事物既可以是可数名词也可以是不可数名词。 (特指，指代单数，指代物，同名同物) Can I borrow your pen—Sorry， I’m using it.
2. one代替前面提到的同类事物中的一个。该事物只能是可数名词,前面可以有冠词,也可以被this、that或形容词修饰,其后也可以有定语。（泛指，指代可数名词，指代人或物，同名异物） I have a bike. Do you have one Eg: (1).I bought a dictionary three years ago and I am still using______ now. (2) I bought a dictionary three years ago but I am going to buy a new _______soon. (3). that代替前面提到的同类事物中特指的一个。该事物既可以是可数名词也可以是不可数名词,必须要有后置定语,但不可以有前置修饰语。（特指，指代单数或不可数，指代物，后面有定语） The coffee produced in Brazil is more famous than __________in Mexico. 四：形式主语、宾语、强调句及其他
临床常见药物用法
盐酸多巴胺注射液【20mg 2ml/支】 【用法】1-5μg/kg*min，每15-30min增加1-4μg/kg*min 【泵入】kg×3+NS 至50ml，1ml/h=1μg/kg*min 【滴入】5%GS 70ml 多巴胺 300mg ，1.2ml/h=1μg/kg*min 【中日急诊】5%GS 100ml 多巴胺 300mg ，5ml/h起(约11.5mg/h,对60kg约3.2ug/kg/min) 盐酸乌拉地尔注射液【亚宁定，25mg 5ml/支】 【用法】25mg+10mlNS慢推一半，15分钟后再推另一半，然后100-400μg/ min(6-24mg/h)维持 【泵入】乌拉地尔100mg NS 30ml ， 3ml/h=6mg/h 【滴入】乌拉地尔 50mg NS 250ml ，10滴/min=30ml/h=6mg/h 【中日急诊】NS 100ml 乌拉地尔 200mg,5ml/h起（约7mg/h） 注射用生长抑素【思他宁3000ug/支*】 【用法】上消化道出血：250μg缓慢注射（>3min），止血后250μg/h维持3-4天，但<120h。 急性胰腺炎：250μg/h维持5-7天 【泵入】生长抑素 6mg NS48ml ，2ml/h=240μg/h；先入2ml。 【滴入】NS或GS 500ml 生长抑素 3mg，ivgtt连续静滴12h。 奥曲肽注射液【善宁，0.1mg 1ml/支】 【用法】25μg缓慢注射，25-50μg/h维持3-4天 【泵入】奥曲肽 0.6 NS 48ml ，2ml/h=24μg/h；先入2ml。 【皮下】预防胰腺手术后并发症，0.1mg 皮下 Q8h×7天，第一次用药至少在术前1小时进行。 注射用甲磺酸加贝酯【100mg/支，70.39元】 【滴入】急性轻型胰腺炎或重症辅助： 加贝酯 100mg 5%GS或林格500ml ，ivgtt（<1mg/kg/h） tid×3天，改为100mg/日，共6-10天 注射用乌司他丁【天普洛安，10万U/支，134.99】 急性胰腺炎、慢性复发性胰腺炎的急性恶化期： 【滴入】5%GS或0.9%NS 500ml 乌司他丁 10万U ，ivgtt 1-2h入 Qd-Tid，随症状改善减量 急性循环衰竭： 【滴入】 5%GS或0.9%NS 500ml 乌司他丁 10万U ，ivgtt 1-2h入 Qd-Tid 【静推】2ml 0.9% NS 乌司他丁 10万U ，缓慢静脉推注 Qd-Tid
It的用法总结
I t的用法总结文档编制序号：[KKIDT-LLE0828-LLETD298-POI08]
It 的用法总结 一. 代词: 1)指代上文 2)指代this/that 3)指代未知性别的婴儿或孩子或身份不明的人 4）指代时间/地点/天气/温度/距离/环境 gets dark very early in the winter. will you call it if it’s a boy love spring---It’s a wonderful time of the year. ’s less than 100 kilometres from here to Jinan. the factory closes, it will mean 500 people losing their jobs. ’s this It’s a cat. has snowed much this year. (1)The book in your bag is very interesting. Can I borrow (2) The book in your bag is more interesting than ______ on the desk. (3) The weather here is much colder than____ in Nanjing. (4) The books are free. You can take____ free of charge. (5) The books in the bag are better than _____ on the desk.
It用法练习题及答案
It的用法 一．单项选择 1.It was at the gate ____ he told me the news. A. that B. what C. which D. when 2.Is ____necessary to tell his father everything A. it B. that C. what D. he 3.Was it in this palace ____ the last emperor died? A. that B. in which C. in where D. which 4.Is ____ possible to fly to the moon in a spaceship? A. now B. man C. that D. it 5.Was it during the Second World War ____he died? A. that B. while C. in which D. then 6.Is ____necessary to complete the design before National Day? A. this B. that C. it D. he 7.I don't think ____possible to master a foreign language without much memory work. A. this B. that C. its D. it 8.Does ____matter if he can't finish the job on time? A. this B. that C. he D. it 9.It was not ____she took off her dark glasses ____ ,I realized she was a famous film star. A. when; that B. until; that C. until; when D. when; then 10.Tom‘s mother kept telling him that he should work harder, but ____didn’t help. A. he B. which C. she D. it 11.____is a fact that English is being accepted as an international language. A. There B. This C. That D. It 12. Is ________ possible to fly to the moon in a spaceship? A．now B．man C．that D．it 13．Our food and service are better than ________ used to be. A．it B．we C．they D．them 14．________ appears to me ________ the report must be truth. A．That; it B．It; that C．It; it D．That; that 15．He feels ________ duty to help others. A．that he B．that his C．it he D．it his 16．Take ________ easy. The roads are icy. A．it B．them C．us D．you 17．The TV sets made in China are much better than ________ in Japan. A．that B．those C．them D．It 18．—— Have you found the bike you lost yesterday? ——Yes, I've found ________ already. A．it B．that C．the one D．that one 19.——I'm looking for a flat.
各种临床使用指南精简版(珍藏版)
中国急性缺血性脑卒中诊治指南 急性期诊断与治疗 一、评估和诊断 (一)病史和体征 1．病史采集：询问症状出现的时问最为重要。 2．一般体格榆查与神经系统体榆：评估气道、呼吸和循环功能后，立即进行一般体格检查和神经系统体检。 3．可用脑卒中量表评估病情严重程度。常用量表有： (1)中国脑卒中患者临床神经功能缺损程度评分量表。 (2)美国国立卫生院脑卒中量表(National Institutes of}tcalth Strok|(NIHss)是目前国际上最常用量表。 (3)斯堪的纳维亚脑卒中量表(ScandinavianStmke Seale，SSS)。 (二)脑病变与血管病变检查 脑部病变检查：1 平扫CT，疑似脑卒中首选检查；2 多模式CT；3 标准MRI；4多模式MRI。 血管检查：1 颈动脉双功超声；2 TCD；3 MRA、CTA、DSA （三）实验室及影像检查选择 所有患者都应做的检查：①平扫脑cT或MRl；②血糖、肝肾功能和电解质；③心电图和心肌缺血标志物；④全血计数，包括血小板计数；⑤凝血酶原时问(Frr)、国际标准化比率(INR)和活化部分凝血活酶时问(AHT)；⑥氧饱和度；⑦胸部x线检查。 部分患者必要时可选择的检查：①毒理学筛查；②血液酒精水平；③妊娠试验；④动脉血气分析(若怀疑缺氧)；⑤腰穿(怀疑蛛网膜下腔出血而cT末显示或怀疑脑卒中继发于感染性疾病)；⑥脑电图(怀疑癫痫发作)。 （四）急性缺血性脑卒中的诊断可根据： (1)急性起病； (2)局灶件神经功能缺损，少数为全面神经功能缺损； (3)症状和体征持续24 h以上（溶栓可参照适应证选择患者）； (4)排除非血管性脑部病变； (5)脑CT或MRI排除脑出血和其他病变，有责任缺血病灶。 （五）急性缺血性脑卒中诊断流程应包括如下5个步骤 (1)是否为脑卒中，排除非血管性疾病。 (2)是否为缺血性脑卒中，进行脑CT或MRI检查排除出血性脑卒中。 (3)脑卒中严重程度，根据神经功能缺损量表评估。 (4)能否进行溶栓治疗，核对适应证和禁忌证（见溶栓中相关内容）。 (5)病因分型参考TOAST标准，结合病史、实验窜、脑病变和血管病变等检查资料确定病因。 推荐意见：(1)对所有疑似脑卒中患者应进行头颅平扫CT或MRI检查（I 级推荐）。(2)在溶栓等治疗前，应进行头颅平扫CT检查（I级推荐）。(3)应进行上述血液学、凝血功能和生化检查（I级推荐）。(4)所有脑卒中患者应进行心电图检查（I级推荐）。(5)用神经功能缺损量表评估病情程度（Ⅱ级推荐）。(6)应进行血管病变检查（Ⅱ级推荐），但在症状出现6 h内，不过分强调此类检查。(7)根据上述规范的诊断流程进行诊断（I级推荐）。
It-的用法总结讲课稿
It 的用法总结 一. 代词: 1)指代上文 2)指代this/that 3)指代未知性别的婴儿或孩子或身份不明的人 4）指代时间/地点/天气/温度/距离/环境 1.It gets dark very early in the winter. 2.What will you call it if it’s a boy? 3.I love spring---It’s a wonderful time of the year. 4.It’s less than 100 kilometres from here to Jinan. 5.When the factory closes, it will mean 500 people losing their jobs. 6.What’s this? It’s a cat. 7.It has snowed much this year. (1)The book in your bag is very interesting. Can I borrow ? (2) The book in your bag is more interesting than ______ on the desk. (3) The weather here is much colder than____ in Nanjing. (4) The books are free. You can take____ free of charge. (5) The books in the bag are better than _____ on the desk.
it用法归纳(高中英语)
“it” 两项重点用法Mar 4. 2011 这两项重点用法指的是强调句和it做形式成分。 一.强调句: 一）陈述句： It + is / was + 被强调部分+ that / who … ( 强调人时可用who ) I met Tom in the street yesterday. 针对各个划线部分变强调句： 1) It was I that met Tom in the street yesterday. 2) It was Tom that I met in the street yesterday. 3) It was in the street that I met Tom yesterday. 4) It was yesterday that I met Tom in the street. 二）一般疑问句： 1) Was it I that met Tom in the street yesterday? 2) Was it Tom that I met in the street yesterday? 3) Was it in the street that I met Tom yesterday? 4) Was it yesterday that I met Tom in the street? 三）特殊疑问句： 1) Who was it that met Tom in the street yesterday? 2) Who was it that I met in the street yesterday? 3) Where was it that I met Tom yesterday? 4) When was it that I met Tom in the street? 四）特殊疑问句作宾语从句： I forgot… 1) I forgot who it was that met Tom in the street yesterday. 2) I forgot who it was that I met in the street yesterday. 3) I forgot where it was that I met Tom yesterday. 4) I forgot when it was that I met Tom in the street. 结论：特殊疑问句作宾语从句时，主谓词序正常。 五）判断强调句的方法： “It is / was … that…” 这个框架拿掉以后，句子仍然成立。 高考题： I just wonder ___ that makes him so excited. A. why it does B. what he does C. how it is D. what it is （D ） 难点： I did not go to bed until midnight. It was not until midnight that I went to bed. 二. It 做形式成分：形式宾语和形式主语
it的用法
一. 基本用法 1. 用作人称代词，代替上文提到过的事物，或事物（同名同物）。The train has arrived. It arrived half an hour ago. I have a car, so you can borrow it. one 指代单数可数名词，同名异物。He has an MP4, but I will buy one tomorrow. that特指单数可数名词或不可数名词。The population of China is larger than that of Japan. The weather of Chongqing is hotter than that of Beijing. 2. 用来代替提示代词this, that。—What’s this?—It’s a knife. —Whose watch is that?—It’s mine. 3. 指代不明性别的人。—Who is knocking at the door? —It’s me. It is a baby. 4. 指环境情况、时间、日期、天气、温度、季节、距离、价格、速度等。It was very noisy at the very moment. —What time is it? —It’s eight o’clock. It often rains in summer here. It is a long way to the school. It is 29 ℃ today. It is five kilometers away. 5. 作形式主语。It is not easy to finish the work in two days. It is no use helping him solve the problem. It is a pity that you didn’t read the book. 6. 作形式宾语。I think it no use arguing with him. I found it very interesting to study English. He made it clear that he was not interested in that subject. 7. 用于强调结构。①It is/was + 被强调部分+ that/who + 原句剩余部分It was Xiaoming whom(that)I met in the street last night. It was in the street that I met Xiaoming last night. It ws last night that I met Xiaoming in the street. It was I who met Xiaoming in the street last night. Was it in the street that you met her? ②特殊疑问词+is/was+it+that+原句剩余部分Who was it that broke the window? What is it that you want me to do? Where was it that he bought the bike?③对until进行强调要把not放在前面。It was not until yesterday that I met my old friend.It was not until he told me that I knew it.④对as,since引导的原因状语从句，要把as,since变成because.It was becaude he got up late that he missed the first bus.⑤判断是否是强调句的方法：It is/was…that/who去掉，看句子是否完整，完整的是强调句。It is there that accidents often happen. It is clear that not all the boys like football. ⑥注意强调句与主语从句、定语从句、状语从句的区别It is a good idea that occurs to me suddenly（强调句）. It is a good idea that we play basketbll after school(主语从句). It is in a small factory that my brother is going to work（强调句）. It is a small factory where my brother is going to work.（定语从句）It wa s five o’clock when the plane landed at the airport(状语从句). It was at five o’clock that the plane landed at the airport（强调句）. 二. 含有it的句型 1.It is time (for sb.) to do sth. It is high/about time that sb. did/should do sth.(虚拟语气) It is time for us to have a rest. It is high time that we took/should take action. It’s about time that we went to the airport. 2. It is + adj. +of / for sb. + to do sth. 形容词为brave, clever, careful, hopeless, kind, good, naughty, nice, silly,stupid,foolish, wise等对人的品质或性格进行评价的词, 一般用 of. It is very kind of you to help me. 3. It is + adj. + that + sb. + (should) do sth.（虚拟语气）, 能用于这个句型的形容词有strange, wonderful, natural, good、proper, right, wrong, well, fortunate, important, necessary, useless, likely, probable, impossible等, 可省去should而直接用动词原形。如：It is important that we should pay close attention to grain. It is natural that he（should）say so. 4. It is no use/ good + doing sth. It is no use trying again. It is no good arguing with your leaders. 5. It is said/reported/announced/ (well) known … that… It is said that he does well in English. 6. It is/was +一段时间+ since … It is three years since I met him in Beijing. It is a long time since I lived in that small mountain village with these farmers.It is five months since I arrived in New York. It is five months since I was in New York. 7.It will be+一段时间+ before …主句的时态可用一般将来时或一般过去时。It will be several years before we meet again. It was not long before they set out for the front. 8. It is /was/will be the first/second/third … time that … It is the first ti me that I have been here. It was the second time that he had seen the film. 9.It is up to sb. to do sth … 应由某人做某事。It is up to you to decide whether we start or not. 10. sb. hate/like/dislike/love/enjoy/resent/appreciate/don’t mind/be fond of/feel like/see to等+it+宾语从句。 I hate it that you can swim so well. I enjoy it when you help someone who is in trouble. 11. It takes sb. some time/ some money to do sth. It took him five years to draw a horse well. 12. 主语+vt.+it+n./adj.+to do sth. I think it hard for you to do the task on you own. 13. 主语+vt.+it+n./adj.+宾语从句。I think it important that you should attend the meeting.
it的用法总结
it的用法总结 :用法英语中it的用法总结 it的用法总结高中 it的用法总结小学 篇一:it的用法归纳 ? Never be afraid of grammar ? Collect some examples; ? Watch them very carefully; ? Find out something in common; ? Try to use the rules ---- practise. it用法完全归纳 一、it 作人称代词的用法 1. 指事物 作为人称代词，it 可以除人以外的一切事物或动物。如: I dropped my watch and it broke. 我把手表掉在地上摔坏了。It’s hard work, but I enjoy it. 工作很辛苦，可是我乐意干。“Where is the dog?” “It’s in the bedroom. ” “狗在哪?”“在卧室里”。 2. 指人 it 指人主要用于指不性别不明的婴儿或用于确认某人的身份。如: Is it a boy or a girl? 是男孩还是女孩? There is a knock on the door. It must be the postman. 有人在敲 门，一定是邮递员。 【说明】在答语中，常用来指本人，如说It’s me。 3. 代替某些代词
代词 it 还可用于代替指示代词this, that 以及复合不定代词 something, anything, nothing等。如: “What’s this?” “It’s a new machine. ” “这是什么?”“是一种新机器”。 Nothing is wrong, is it? 没出什么问题，是吗? 二、it 作非人称代词的用法 1. 基本用法 it 作非人称代词的用法，主要用于指时间、距离、价值、天气、气候及温度等自然现象。如: It’s too late to go there now. 现在去那儿已经太迟了。 It rained all day yesterday. 昨天下了一天的雨。 It can get very hot here. 这里有时会很热。 2. 用于某些句型 It’s time for sth. 该做某事了。 It’s time to do sth. 该做某事的时候了。 It’s time for sb to do sth. 某人该干某事了。 It’s (about / high) time + that-从句. 某人该做某事了。(从句谓语用过去式，有时也用“should+动词原形”) It’s first (second) time + that-从句. 某人第几次干某事。(从句谓 语用现在完成时) It’s + 时间段 + since-从句. 自从……有一段时间了。 It’s + 时间段 + before-从句. 过多长的时间才…… 三、it用作形式主语 1. 基本用法
it在从句中的用法
1、It is＋被强调部分＋that …该句型是强调句型。将被强调的部分放在前面，其它部分置于that 之后。被强调部分可以是主语，宾语，表语或状语。强调的主语如果是人，that 可以由who 换用。如果把这种句型结构划掉后，应该是一个完整无缺的句子。这也是判断强调句型与其它从句的方法。 It was about 600 years ago that the first clock with a face and an hour hand was made. It was they that（who）cleaned the classroom yesterday. It was in the street that I met her father. 2、It is important（necessary, right, strange, natural…）that …该句型和上一个同属一种句型。由于主句中的形容词不同，that 后的从句中要用虚拟语气（should＋动词原形），should 可以省去。建议记住该句型中的形容词。 It is important that we（should）learn English well. It is necessary that he（should）remember these words. 3、It is said（reported, learned…）that …该句型中的it 仍是形式主语，真正主语是that 引导的主语从句。该结构常译为“ 据说（据报道，据悉……）”。 It is said that he has come to Beijing. It is reported that another man-made satellite has been put into orbit. 4. It is suggested（ordered, required …）that …该句型和上一个同属一种句型。主句中的过去分词是表示请求，建议，命令等词时，that 后的从句要用虚拟语气（should＋动词原形），should 可以省。常译为“ 据建议；有命令……”。 It is suggested that the meeting（should）be put off. It was ordered that we（should）arrive there in two hours. 5、It is a pity（a shame …）that …该句型中，that 后的从句一般用虚拟语气（should＋动词原形），should 可省去. 表示出乎意料，常译为“竟然”。没有这种意义时，则不用虚拟语气。 It is a pity that such a thing（should）happen in your class. It is a pity that he is ill. 6. It is the first（second …）time that …该句型要和上一个句型区别开来。该句型中的that 从句不用虚拟语气，而用完成时态。至于用什么完成时态，由主句的谓语动词的时态决定。如果是一般现在时，后面从句用现在完成时态；如果是一般过去时，后面从句则用过去完成时态。该结构中that 可以省去；it 有时用this 替换，常译为“是第一（二）……次……”。 It is the first time I have been here. ＝This is the first time I have been here. 7.It is … since … 该句型主要用作处理瞬间动词的完成时，又要和表示一段时间的时间状语连用的问题。主句中是时间作表语，其时态是现在时或完成时，since 引导的从句通常是一般过去时态，而且是瞬间动词。如果主句是一般过去时，从句则用过去完成时。 It is（has been）5 years since his father died. 8. It be … before …该句型主句中的it 指时间, 主句中的时态常是将来一般时或过去时两种时态. 主句中的表语多是long, not long , 3 days , 2 weeks 等表示时间段的词或短语。常译为“……之后……”。 It was 3 days before he went to Beijing. It will be not long before he finishes his job. 13. It happens（seems, looks, appears）that…该句型中it是形式主语，that 引导的是主语从句，主句的happen, seem 等词是不及物动词。 It happened（so happened）that he met his teacher in the street. 碰巧…… It seems that he will be back in a few days. 看来……
临床常用药物――用法用量
临床常用药物――用法用量 一、阿托品注射液（规格：多种） [适应症] 各种内脏绞痛，如胃肠绞痛及膀胱刺激症。对胆绞痛及肾绞痛的疗效较差；全身麻醉前给药，严重盗汗和流涎症；迷走神经过度兴奋导致的窦房阻滞、房室阻滞等缓慢型心律失常；抗休克；解救有机磷酯类中毒。 [用法用量] 1、皮下或静脉注射成人常用量：0.3-0.5mg/次，小儿常用量：0.01-0.02mg/Kg/次，极量2.0mg/次。 2、抗心律失常成人静脉注射0.5-1mg，按需可1-2小时一次，最大量为2mg。 3、解毒有机磷中毒：轻度，静注1-2mg/1－2小时/次，阿托品化后0.5mg/4－6小时/次。中度，静注2-4mg/15－30分钟/次，阿托品化后0.5 mg－1mg/4－6小时/次。重度，静注5-10mg/10－30分钟/次，阿托品化后0.5mg－1mg/2－4小时/次。 [禁忌] 青光眼及前列腺肥大者、高热者禁用。静脉每次极量2mg，超过上述用量，会引起中毒。最低致死量成人约80-130mg。 [不良反应]:外周反应；中枢兴奋时可用安定治疗。 二、654-2（盐酸消旋山莨菪碱注射液）（规格：1ml:5mg/支） [适应症]胃肠绞痛、感染性休克。 [用法用量] 1、常用量：成人肌注5--10mg,小儿0.1--0.2mg/Kg/次。每日1--2次。 2、抗休克及有机磷中毒：静注，成人每次10--40mg,小儿每次0.1--0.2mg/Kg,必要时每10-30分钟重复给药，也可增加剂量。病情好转后逐渐延长给药间隔，至停药。 [禁忌]颅内压增高、脑出血急性期、青光眼、幽门梗阻、肠梗阻及前列
腺肥大者禁用；反流性食管炎，溃疡性结肠炎慎用。 三、碘解磷定（0.5g/支） [适应症]解救有机磷农药中毒，对乐果无效。 [用法用量] 轻度中毒：0.25－0.5g肌注，必要时2小时重复1次；中度中毒：首次0.5－0.75g肌注或静滴，必要时2小时后肌注0.5g。重度中毒：首次1g静注30－60分钟后无好转再给0.5－0.75g肌注或静滴后改为0.25－0.5g/小时静滴，好转停药。 [禁忌]禁与碱性药物混合用，因为在碱性溶液中可分解生成剧毒氰化物。 四、盐酸肾上腺素（规格：1.0mg/支) [适应症]支气管痉挛所致严重呼吸困难、过敏性休克、心脏骤停。 [用法用量] 常用量皮下或肌注0.25mg-1.0mg/次；极量1.0mg/次。抢救过敏性休（1）皮下或肌注0.5-1.0mg/次；极量 1.0mg/次；（2）静推：0.1mg---0.5mg用0.9%氯化钠液10ml缓慢静推；（3）如果疗效不佳可用4--8mg与500--1000ml葡萄糖静滴。 [禁忌] 1、下列情况应慎用：器质性脑病、心血管病、青光眼、帕金森氏病、噻嗪类引起的循环虚脱及低血压、精神、神经疾病。 2、用量过大或皮下注射误入血管时可引起血压突然升高而致脑溢血。 3、抗过敏性休克时，需补充血容量。 [不良反应]中枢兴奋、血压突升、心律失常。 五、多巴胺注注射液（20mg/2ml/支） [适应症] 治疗休克、急性肾功能衰竭。 [用法用量] 小剂量5～10ug/kg/min：扩张内脏及肾血管，降低外周阻力；中剂量10～20ug/kg/min：除扩血管外，尚有正性肌力作用；大剂量大于20ug/kg/min：可使肺血管收缩，外周阻力增加。极量：20ug/kg/min。[禁忌]禁用于心动过速及室颤。 六、酚妥拉明（5mg/ml/支）