高一英语下册单元知识点课件18

1、Unit 4 Global warmingUnit 4 Global warming基础落实基础落实.高频单词思忆高频单词思忆1.She doesnt want to make a big emotional 1.She doesnt want to make a big emotional ( (承诺承诺) to Steve at the moment.) to Steve at the moment.2.Under no 2.Under no ( (情况情况) should you ) should you lend Paul any money. lend Paul any money.

2、3.The electricity industry 3.The electricity industry ( (消耗消耗) ) large quantities of fossil fuels. large quantities of fossil fuels.4.There are a lot of natural 4.There are a lot of natural ( (现象现象) ) we cant understand. we cant mitmentcommitmentcircumstancescircumstancesconsumesconsumesphenomenaphe

3、nomena5.If you behave so foolishly you must be 5.If you behave so foolishly you must be ready to take the ready to take the ( (后果后果).).6.Large 6.Large ( (量量) of money have been ) of money have been spent on the bridge. spent on the bridge.7.Which journals does the library s7.Which journals does the

4、library s to? to? 8.I would 8.I would o o changing the law. changing the law. 9.This 9.This d d was collected from 69 countries. was collected from 69 countries.10.He has already 10.He has already s s his intention to his intention to run for election. run for election.consequenceconsequencequantiti

5、esquantitiesubscribeubscribepposepposeataatatatedtated.重点短语再现重点短语再现1.1. 发生；造成发生；造成2.2. 代表代表一方，作为一方，作为的代言人的代言人3.3. 同意，赞成；订购同意，赞成；订购4.4. 反对反对5.5. 继续继续6.6. 导致导致7.7. 忍受，容忍忍受，容忍8.8. 上升；增长；升起上升；增长；升起9.9. 只要只要10.10. 即使即使come aboutcome abouton behalf ofon behalf ofsubscribe tosubscribe tobe opposed tobe opp

6、osed tokeep onkeep onresult inresult input up withput up withgo upgo upso long asso long aseven ifeven if.典型句式运用典型句式运用1.It takes a lot of energy to make things 1.It takes a lot of energy to make things from new materials,. from new materials,.用新原料造东西需要大用新原料造东西需要大 量能源，量能源， 句中句中itit为为 ，taketake意为：意为：

7、（时间、劳力等）；有这种含义的（时间、劳力等）；有这种含义的taketake通常通常 不可用于被动语态。比较：不可用于被动语态。比较：It takes sb.time to It takes sb.time to do sth. do sth.某人花费时间做某事。某人花费时间做某事。考点提炼考点提炼 形式主语形式主语需要需要,消耗消耗2.Its OK to leave an electrical appliance 2.Its OK to leave an electrical appliance on so long as you are using it-if not,turn on so

8、 long as you are using it-if not,turn it off! it off!只要你在使用电器设备，你便可以把它开只要你在使用电器设备，你便可以把它开 着。如果不用就把它关掉！着。如果不用就把它关掉！ so/as long asso/as long as引导引导 从句，意从句，意 为为“ ”。另外此短语还可意为。另外此短语还可意为“在在的时的时 间之内；既然，因为间之内；既然，因为”等。等。考点提炼考点提炼 条件状语条件状语只要只要3.“We cant predict the climate well enough 3.“We cant predict the cl

9、imate well enough to know what to expect,. to know what to expect,.我们预报气候不够我们预报气候不够 准确以致于不能知道要发生的事，准确以致于不能知道要发生的事， not.enough to do sth. not.enough to do sth.意为：意为： “ “ ”；enoughenough表示它前表示它前 面的形容词、副词的程度，面的形容词、副词的程度， 表示由此产生表示由此产生 的结果或行动，的结果或行动，enoughenough后面后面 thatthat从句。从句。考点提炼考点提炼 不够不够以致于不能以致于不能不定

10、式不定式不能不能课堂导练互动课堂导练互动重点单词重点单词1.quantity1.quantity The problem begins when we add huge The problem begins when we add huge of extra carbon dioxide into the of extra carbon dioxide into the atmosphere. atmosphere. （回归课本（回归课本P P2626） 观察思考观察思考 He prefers quantity to quality when food is He prefers quanti

11、ty to quality when food is concerned. concerned. 就食物而言，他讲究量不讲究质。就食物而言，他讲究量不讲究质。 Quantities of food and tents were sent to Quantities of food and tents were sent to Wenchuan from Shandong. Wenchuan from Shandong. 大量的食品和帐篷被从山东运往汶川。大量的食品和帐篷被从山东运往汶川。quantitiesquantities归纳总结归纳总结quantity quantity 。in quan

12、tityin quantity大量大量a large quantity ofa large quantity of许多，大量，既可修饰可数名许多，大量，既可修饰可数名词复数，也可修饰不可数名词。词复数，也可修饰不可数名词。n n. .量；数量量；数量quantities of+quantities of+不可数名词不可数名词可数名词复数可数名词复数复数谓复数谓语动词语动词+ +许多的，大量的许多的，大量的quantity of+quantity of+可数名词复数可数名词复数+ +复数谓语动词复数谓语动词不可数名词不可数名词+ +单数谓语动词单数谓语动词许多的，大量的许多的，大量的注意注意 a

13、 quantity ofa quantity of后同样可接不可数名词或可数后同样可接不可数名词或可数名词的复数形式。但当它作主语时谓语动词一般根名词的复数形式。但当它作主语时谓语动词一般根据其所修饰的名词而定，而据其所修饰的名词而定，而quantities ofquantities of作主语作主语时，不论其后的名词可数或不可数，谓语动词都用时，不论其后的名词可数或不可数，谓语动词都用复数。复数。即学即用即学即用用用quantityquantity的相关短语填空的相关短语填空(1)Its a lot cheaper if you buy it(1)Its a lot cheaper if y

14、ou buy it . . (2)My brother bought(2)My brother bought books. books. (3)There are (3)There are rain in rain in this area. this area.in quantityin quantitya large quantity ofa large quantity oflarge quantities oflarge quantities of2.oppose2.oppose .,who are .,who are to this view and to this view and

15、 believe that we should not worry about high believe that we should not worry about high levels of carbon dioxide in the air. levels of carbon dioxide in the air. （回归课本（回归课本P P2727） 观察思考观察思考 He threw all those that opposed him into He threw all those that opposed him into prison. prison. 他把所有反对他的人都投

16、进了监狱。他把所有反对他的人都投进了监狱。 I oppose you going there alone.I oppose you going there alone. 我反对你单独去那儿。我反对你单独去那儿。opposedopposed归纳总结归纳总结oppose oppose vtvt. . 。oppose sth./doing sth./sb.doing sth.oppose sth./doing sth./sb.doing sth.反对某事反对某事/ /做某事做某事/ /某人做某事某人做某事oppose sth.to/against sth.oppose sth.to/against

17、sth.使某事物与另一事物使某事物与另一事物对照对照/ /对抗对抗opposed opposed adjadj. .相反的；对立的相反的；对立的be opposed tobe opposed to反对；与反对；与对立对立反对，反抗；与（某人）较量反对，反抗；与（某人）较量即学即用即学即用(1)(1)他反对修建新礼堂的建议。他反对修建新礼堂的建议。 He He to build a new to build a new hall. hall. (2)(2)不要用你的意愿和我的相抗衡。不要用你的意愿和我的相抗衡。 Do not Do not your will your will mine. mi

18、ne.(3)(3)她好像很反对你出国。她好像很反对你出国。 She seems very much She seems very much your going your going abroad. abroad.opposed the proposalopposed the proposalopposeopposeagainstagainstopposed toopposed to3.range3.range It will make plants grow quicker;crops will It will make plants grow quicker;crops will prod

19、uce more;it will encourage a greater produce more;it will encourage a greater of animals. ( of animals. (回归课本回归课本P P2727) ) 观察思考观察思考 The price of the house is well beyond our The price of the house is well beyond our range. range. 这所房子的价格远远超过了我们能承受的范围。这所房子的价格远远超过了我们能承受的范围。 There are 120 students who

20、se ages range There are 120 students whose ages range from 10 to 18. from 10 to 18. 有有120120名学生年龄在名学生年龄在1010到到1818岁之间。岁之间。rangerangeThere will be an increase in the range of 1 There will be an increase in the range of 1 to 3 percent.to 3 percent.将会有将会有1 1到到3 3个百分点的增长幅度。个百分点的增长幅度。The show ranges over

21、 many settings,from 18thThe show ranges over many settings,from 18thcentury sailing ships to concert halls.century sailing ships to concert halls.这个节目涉及许多场景：从这个节目涉及许多场景：从1818世纪的帆船到音乐厅。世纪的帆船到音乐厅。归纳总结归纳总结range range 。(1)a wide range of(1)a wide range of一系列一系列a full range ofa full range of各种各种in/within

22、 rangein/within range在射程以内；在在射程以内；在范围内范围内beyond/out of rangebeyond/out of range在射程外；在在射程外；在范围外范围外in/out of the range ofin/out of the range of在在/ /超出超出范围范围out of ones rangeout of ones range某人能力达不到的；某人知识某人能力达不到的；某人知识以外的以外的(2)range from.to.(2)range from.to.在在范围内变动；包括范围内变动；包括（由（由到到）之间的各类事物）之间的各类事物range

23、between.and.range between.and.在在和和范围内变动范围内变动n n. .种类；范围；幅度；界限；种类；范围；幅度；界限；v v. .（在一定范围内）变动，变化；排列（在一定范围内）变动，变化；排列即学即用即学即用(1)(1)这家商店商品品种繁多。这家商店商品品种繁多。(2)(2)年龄范围从年龄范围从6 6岁到岁到1212岁。岁。(3)(3)老师沿着小径排列他的学生。老师沿着小径排列他的学生。The shop keeps a wide range of goods.The shop keeps a wide range of goods.The age range i

24、s from 6 to 12 years.The age range is from 6 to 12 years.The teacher ranged his students alongThe teacher ranged his students alongthe path.the path.4.glance4.glance quickly at the magazine article and quickly at the magazine article and answer the questions. answer the questions. （回归课本（回归课本P P2727）

25、 观察思考观察思考 He glanced nervously at his watch.He glanced nervously at his watch. 他紧张不安地看了一下表。他紧张不安地看了一下表。 Nadine glanced round to see if there was Nadine glanced round to see if there was anyone that she knew. anyone that she knew. 纳丁快速环视了一下，看看是否有她认识的人。纳丁快速环视了一下，看看是否有她认识的人。GlanceGlanceHe gave her a qu

26、ick glance as she walked He gave her a quick glance as she walked into the o the room.她走进房间时，他朝她看了一眼。她走进房间时，他朝她看了一眼。One glance at her face told me that she was One glance at her face told me that she was tired.tired.一看她的脸色，我就知道她累了。一看她的脸色，我就知道她累了。归纳总结归纳总结glance glance 。glance at/over/throughg

27、lance at/over/through浏览；匆匆地看一眼浏览；匆匆地看一眼glance offglance off擦过；掠过擦过；掠过glance around/roundglance around/round环视环视at a glanceat a glance一眼；立刻一眼；立刻at first glanceat first glance乍一看；乍看之下乍一看；乍看之下take/have a glance attake/have a glance at匆匆看一眼匆匆看一眼steal a glancesteal a glance偷偷看一眼偷偷看一眼vivi. .看一下；扫视；看一下；扫视；

28、n n. .一瞥一瞥易混辨异易混辨异glance,glare,stare,glimpseglance,glare,stare,glimpse(1)glance(1)glance指很快地看某人或某物一眼。指很快地看某人或某物一眼。(2)glare(2)glare指怒视。指怒视。(3)stare(3)stare指由于生气、好奇、害怕或吃惊而睁大眼指由于生气、好奇、害怕或吃惊而睁大眼睛注视某人或某物。睛注视某人或某物。(4)glimpse(4)glimpse意为意为“瞥见瞥见”，强调结果。，强调结果。即学即用即学即用(1)(1)他扫视了一下会议室。他扫视了一下会议室。 He He the confe

29、rence room. the conference room.(2)(2)他瞥了一眼那个信封，认出是他叔父的笔迹。他瞥了一眼那个信封，认出是他叔父的笔迹。 He He the envelope and recognized the envelope and recognized his uncles handwriting. his uncles handwriting.(3)(3)球从球门柱上斜擦入网。球从球门柱上斜擦入网。 The ball The ball the post into the net. the post into the net.(4)(4)他一眼就看出了问题所在。他一

30、眼就看出了问题所在。 He could tell He could tell what was wrong. what was wrong.glanced aroundglanced aroundglanced atglanced atglanced offglanced offat a glanceat a glance5.average5.average The greenhouse effect gives the earths The greenhouse effect gives the earths surface the surface the temperature of 15

31、. temperature of 15. ( (回归课本回归课本P P2929) ) 观察思考观察思考 Do you know what the average rainfall is Do you know what the average rainfall is for the winter in our area? for the winter in our area? 你知道我们地区冬季的平均降雨量是多少吗？你知道我们地区冬季的平均降雨量是多少吗？ averageaverageUsually,children of average intelligence Usually,childr

32、en of average intelligence achieve good results in study thanks to achieve good results in study thanks to their diligence.their diligence.通常智力水平中等的孩子往往会由于勤奋而成绩突通常智力水平中等的孩子往往会由于勤奋而成绩突出。出。There is nothing special about it.It is only There is nothing special about it.It is only average.average.它没什么特别之

33、处，很普通。它没什么特别之处，很普通。归纳总结归纳总结average average adjadj. . ；n n. . ； 平均平均为；计算出为；计算出的平均数。的平均数。(1)an average rate/cost/price(1)an average rate/cost/price平均比率平均比率/ /成本成本/ /价价格格an average of an average of 的平均数的平均数above/below averageabove/below average高于高于/ /低于平均水平低于平均水平on averageon average平均地；通常；按平均值平均地；通常；按平

34、均值up to averageup to average达到平均数；达到一般水准达到平均数；达到一般水准(2)average out (at sth.)(2)average out (at sth.)平均数为；扯平；最终平均数为；扯平；最终达到平衡达到平衡average sth.outaverage sth.out算出算出的平均数的平均数平均的，普通的平均的，普通的平均数平均数v.v.即学即用即学即用用适当的介词填空用适当的介词填空(1)(1) average men smoke more cigarettes average men smoke more cigarettes than wo

35、men. than women.(2)His living standards are (2)His living standards are average average ( (低于一般水平低于一般水平).).(3)My school work is well (3)My school work is well average. average.(4)The average age (4)The average age the boys in this the boys in this class is fifteen. class is fifteen.OnOnbelowbelowabo

36、veaboveofof重点短语与句型重点短语与句型e e about So how has this So how has this and does it and does it matter? ( matter? (回归课本回归课本P P2626) ) 观察思考观察思考 They didnt know how the change had come They didnt know how the change had come about. about. 他们不知道这个变化是怎么发生的。他们不知道这个变化是怎么发生的。 Many a quarrel comes about through

37、a Many a quarrel comes about through a misunderstanding. misunderstanding. 很多争吵是由误解引起的。很多争吵是由误解引起的。come aboutcome about归纳总结归纳总结come aboutcome about意为：意为： ，是，是 短语，短语，不能接宾语，也没有被动语态。不能接宾语，也没有被动语态。与与comecome相关的短语：相关的短语：come acrosscome across偶然遇见；无意中找到偶然遇见；无意中找到come oncome on跟着来，跟上来；口得啦；快点跟着来，跟上来；口得啦；快点c

38、ome outcome out出来，出现；（芽）生出来；（花）开；出来，出现；（芽）生出来；（花）开；出版，发行出版，发行come tocome to总计；达到；归纳为总计；达到；归纳为come upcome up走近；上（楼）去；（从土中）长出，发走近；上（楼）去；（从土中）长出，发芽；被提出；流行起来芽；被提出；流行起来come up withcome up with找到（答案）；拿出（一笔钱等）找到（答案）；拿出（一笔钱等）发生发生,造成造成不及物动词不及物动词即学即用即学即用用用comecome的相关短语填空的相关短语填空(1)She (1)She a new idea for inc

39、reasing a new idea for increasing sales. sales.(2)He never remembered having (2)He never remembered having a a man like that. man like that.(3)Tell me how the accident (3)Tell me how the accident . .(4)His new book will (4)His new book will next year. next year.came up withcame up withcome acrosscom

40、e acrosscame aboutcame aboutcome outcome out7.result in7.result in They also agree that it is the burning of They also agree that it is the burning of more and more fossil fuels that has more and more fossil fuels that has this increase in carbon dioxide. this increase in carbon dioxide. ( (回归课本回归课本

41、P P2626) ) 观察思考观察思考 The fire resulted in eleven people being The fire resulted in eleven people being killed and the destruction of the factory. killed and the destruction of the factory. 火灾造成了十一人死亡，工厂被烧毁。火灾造成了十一人死亡，工厂被烧毁。 The fresh policy results in economic The fresh policy results in economic dev

42、elopment. development. 那项新政策促进经济发展。那项新政策促进经济发展。resultedresultedinin归纳总结归纳总结resultresult是是 动词，与动词，与inin连用，表示连用，表示“ ”，句子的主语是原因，句子的主语是原因，inin的宾语是结果。的宾语是结果。result fromresult from起因于；因起因于；因而造成而造成as a resultas a result结果；因此结果；因此with the result that.with the result that.为此，因此为此，因此as a result ofas a result

43、of作为作为的结果的结果without resultwithout result毫无结果地毫无结果地不及物不及物引起某种引起某种结果结果即学即用即学即用(1)(1)成功来自努力工作。成功来自努力工作。 Success Success hard work. hard work.(2)(2)他的粗心致使他犯了一个严重的错误。他的粗心致使他犯了一个严重的错误。 His carelessness His carelessness a serious a serious blunder. blunder.(3)(3)我在浴室，因此没听见电话。我在浴室，因此没听见电话。 I was in the bath

44、room, I was in the bathroom, I didnt hear the telephone. I didnt hear the telephone.(4)(4)这种化学物质因一种化学反应而形成。这种化学物质因一种化学反应而形成。 The chemical substance formedThe chemical substance formed a chemical reaction. a chemical reaction.results fromresults fromresulted inresulted inwith the result thatwith the

45、result thatas a resultas a resultofof8.put up with8.put up with We dont have to We dont have to pollution. pollution. （回归课本（回归课本P P3030） 观察思考观察思考 I cant put up with these insults any more.I cant put up with these insults any more. 我不能再忍受这样的侮辱了。我不能再忍受这样的侮辱了。 You see what I have to put up with!You see

46、 what I have to put up with! 你看到我不得不忍受些什么了吧！你看到我不得不忍受些什么了吧！ We had to put up with the inconvenience.We had to put up with the inconvenience. 我们不得不忍受这种不便。我们不得不忍受这种不便。put up withput up with归纳总结归纳总结put up withput up with意为：意为： 。（1 1）put acrossput across解释；表达解释；表达put asideput aside节省；储蓄，储存节省；储蓄，储存put do

47、wnput down写下，记下；击败；平定写下，记下；击败；平定put forwardput forward提出建议；把提出建议；把向前拨向前拨put offput off延期，推迟延期，推迟put onput on穿上，戴上；演出穿上，戴上；演出put output out熄灭；扑灭熄灭；扑灭put throughput through接通电话接通电话（2 2）keep up withkeep up with与与保持一致；不落后保持一致；不落后catch up withcatch up with赶上，追上赶上，追上come up withcome up with赶上；提出赶上；提出容忍，忍受

48、容忍，忍受即学即用即学即用(1)(1)我再也忍受不住牙痛，于是就去找牙科医生诊治。我再也忍受不住牙痛，于是就去找牙科医生诊治。 No longer being able to No longer being able to my my toothache,I went to consult a dentist. toothache,I went to consult a dentist.(2)(2)她知道如何把歌唱得传神。她知道如何把歌唱得传神。 She knows how to She knows how to . .(3)(3)天黑下来了，他在山脚下的一棵大树下搭起帐篷天黑下来了，他在山脚

49、下的一棵大树下搭起帐篷 准备过夜。准备过夜。 It was becoming dark,and heIt was becoming dark,and he under a big tree at the foot of the hill under a big tree at the foot of the hill for the night. for the night.(4)(4)史密斯先生把几块史密斯先生把几块“禁止停车禁止停车”的牌子挂在大门的牌子挂在大门 外边，但没有任何效果。外边，但没有任何效果。 Mr.SmithMr.Smith outside his gate,but thi

50、s has not had any outside his gate,but this has not had any effect. effect.put up withput up withput a song acrossput a song acrossput up a tentput up a tenthas put up “No Parking” signshas put up “No Parking” signs9.There is no doubt that the earth is 9.There is no doubt that the earth is becoming

51、warmer (see Graph 1) and that becoming warmer (see Graph 1) and that it is human activity that has caused it is human activity that has caused this global warming rather than a random this global warming rather than a random but natural phenomenon. but natural phenomenon.毫无疑问，地球正毫无疑问，地球正 变得更加暖和（见图表变

52、得更加暖和（见图表1 1），而且全球变暖是），而且全球变暖是 人为的，而不是随意的自然现象。人为的，而不是随意的自然现象。 典例体验典例体验 you will succeed if you will succeed if you try your best. you try your best. 毫无疑问如果你尽最大努力你一定会成功。毫无疑问如果你尽最大努力你一定会成功。 Americans are deep Americans are deep in love with the computer. in love with the computer. 毫无疑问，美国人已深深爱上了电脑。毫无疑

53、问，美国人已深深爱上了电脑。There is no doubt thatThere is no doubt thatThere is no doubt thatThere is no doubt that归纳总结归纳总结在在There is (have) no doubtThere is (have) no doubt后常可跟后常可跟 引导的引导的从句；在肯定句中，从句；在肯定句中，doubtdoubt后面有时可跟后面有时可跟引导的从句。引导的从句。（1 1）在本句型中，）在本句型中，thatthat从句是同位语从句，表示从句是同位语从句，表示doubtdoubt的内容。用法与的内容。用法与T

54、here is a chance that.There is a chance that.是一样的。是一样的。doubtdoubt作为名词，若用在否定句或疑问句中，后面作为名词，若用在否定句或疑问句中，后面接接thatthat引导的同位语从句；若用在肯定句中，后面引导的同位语从句；若用在肯定句中，后面接接whetherwhether引导的同位语从句。注意此时不可以用引导的同位语从句。注意此时不可以用ifif替换替换whetherwhether。thatthatwhetherwhetherdoubtdoubt作为动词，若用于否定句和疑问句中，后面作为动词，若用于否定句和疑问句中，后面接接that

55、that引导的宾语从句；若用于肯定句中，后面一引导的宾语从句；若用于肯定句中，后面一般接般接whetherwhether或或ifif引导的宾语从句。引导的宾语从句。（2 2）doubtdoubt组成的一些短语：组成的一些短语：in doubtin doubt怀疑；拿不定主意怀疑；拿不定主意no/without/beyond doubtno/without/beyond doubt无疑地，必定无疑地，必定常用结构：常用结构：There is no/some room for doubt.There is no/some room for doubt.没有怀疑余没有怀疑余地地/ /有可疑处有可疑处

56、There is no knowing/telling.There is no knowing/telling.没法知道没法知道/ /说说There is no need.There is no need.没有必要没有必要There is no question.There is no question.没有问题没有问题There is no reason.There is no reason.没有理由没有理由There is no possibility that.There is no possibility that.是没有可能是没有可能的的It is no/small wonder t

57、hat/No wonder (that).It is no/small wonder that/No wonder (that).难怪难怪It is a wonder that.It is a wonder that.真奇怪真奇怪/ /真是令人惊奇真是令人惊奇即学即用即学即用(1)(1)毫无疑问，他们在这件事上会同意你的。毫无疑问，他们在这件事上会同意你的。 they will agree they will agree with you on this matter. with you on this matter.(2)(2)我相信他会成功的。我相信他会成功的。 I I he will s

58、ucceed. he will succeed.(3)(3)公共图书馆的前途难以预料。公共图书馆的前途难以预料。 The future of the public library isThe future of the public library is . . (4)(4)萨莉确实是学校最优秀的游泳者之一。萨莉确实是学校最优秀的游泳者之一。 Sally was Sally was one of one of the finest swimmers in the school. the finest swimmers in the school.There is no doubt thatTh

59、ere is no doubt thathave no doubt thathave no doubt thatin doubtin doubtno/without/beyond doubtno/without/beyond doubt考题回扣考题回扣【例例1 1】You may use the room as you like You may use the room as you like you clean it up afterwards. you clean it up afterwards. （北京高考）（北京高考） A.so far asA.so far asB.so long

60、asB.so long as C.in case C.in caseD.even ifD.even if 解析解析 句意为：你尽可随意使用这个房间，只要句意为：你尽可随意使用这个房间，只要 你过后打扫干净即可。你过后打扫干净即可。so far asso far as远到；就远到；就而而 言；言；so long asso long as只要；只要；in casein case以防（万一）；以防（万一）； even ifeven if即使。即使。 课文原文课文原文 It is OK to leave an It is OK to leave an electrical applianceelect