高一英语必修三 UNIT 4课文详解

高一英语必修三高一英语必修三 UNIT 4 UNIT 4课文详解课文详解1.Nooneknowsexactlyhowtheearthbegan,asithappenedsolongago.没有人确切知道地球是怎样开始形成的，因为在很早很早以前地球就形成了。2.However,accordingtoawidelyacceptedtheory,theuniversebeganwithaBigBangthatthrewmatterinalldirections.然而，一种普遍为人们所接受的理论是：宇宙起源于一次大爆炸，这次大爆炸将物质投射到四面八方。3.Afterthat,atomsbegantoformandcombinetocreatestarsandotherbodies.然后，原子开始形成并结合成恒星和其他天体。Par11.ForseveralbillionyearsaftertheBigBang,theearthwasstilljustacloudofdust.大爆炸后好几十亿年过去了，但地球还只是一团尘埃。2.Whatitwastobecomewasuncertainuntilbetween4.5and3.8billionyearsagowhenthedustsettledintoasolidglobe.随后它会变成什么没人能知道，直到3845亿年前，这团尘埃才慢慢地形成一个固体的球状物。3.Theearthbecamesoviolentthatitwasnotclearwhethertheshapewouldlastornot.地球（开始）变得激烈动荡，不知道这个固体形状是否会继续存在下去。Par24.Itexplodedloudlywithfireandrock.Theywereintimetoproducecarbon,nitrogen,watervapourandothergases,whichweretomaketheearthsatmosphere.它（地球）猛烈地爆炸喷出了烈火与岩石，最终产生了碳，氮气，水蒸气和其他多种气体，从而形成了地球的大气层。5.Whatisevenmoreimportantisthatastheearthcooleddown,waterbegantoappearonitssurface.更为重要的是，地球冷却了下来，地球的表面就开始出现了水。1.WaterhadalsoappearedonotherplanetslikeMarsbut,unliketheearth,ithaddisappearedlater.在火星这些其他行星上都出现了水，但和地球不同的是，这些水后来都消失了。2.Itwasnotimmediatelyobviousthatwaterwastobefundamentaltothedevelopmentoflife.水对于生命的发展会起关键作用，这一点在当时并不明显。3.Whatmanyscientistsbelieveisthatthecontinuedpresenceofwaterallowedtheearthtodissolveharmfulgasesandacidsintotheoceansandseas.很多科学家相信，由于地球上长期有水存在，使得地球得以把有害气体和酸性物质溶解在海洋里。4.Thisproducedachainreaction,whichmadeitpossibleforlifetodevelop.这就产生了一系列的反应，使得生命就有可能开始发展了。Par31.Manymillionsofyearslater,thefirstextremelysmallplantsbegantoappearonthesurfaceofthewater.好几百万年后，水的表面开始出现了极小的植物。2.Theymultipliedandfilledtheoceansandseaswithoxygen,whichencouragedthelaterdevelopmentofearlyshellfishandallsortsoffish.他们繁殖起来就使得海洋充满了氧气，这为早期的贝类及其他各种鱼类后来的进化创造了条件。3.Next,greenplantsbegantogrowonland.Theywerefollowedintimebylandanimals.接着，绿色植物开始出现在陆地上。4.Somewereinsects.Others,calledamphibians,wereabletoliveonlandaswellasinthewater.随后，陆地上出现了动物，其中有一些是昆虫，另外一些叫两栖动物，他们既能在陆上生活，也能在水里生存。Par45.Laterwhentheplantsgrewintoforests,reptilesappearedforthefirsttime.后来，当植物长成了森林的时候，爬行动物首次出现了。6.Theyproducedyoungentirelybylayingeggs.他们一般是通过孵蛋而繁衍后代的。7.Afterthat,somehugeanimals,calleddinosaurs,developed.再后来一些叫做恐龙的巨型动物出现了。8.Theylaideggstooandexistedontheearthformorethan140millionyears.他们也生蛋，在地球上生存了一亿四千多万年。9.However,65millionyearsagotheageofthedinosaursended.然而，六千五百万年前，恐龙时代结束了。10.Whytheysuddenlydisappearedstillremainsamystery.他们为什么会突然灭绝至今仍是个谜。11.Thisdisappearancemadepossibletheriseofmammalsontheearth.恐龙的灭绝使地球上哺乳动物的增多有了可能。12.Theseanimalsweredifferentfromalllifeformsinthepast,becausetheygavebirthtoyoungbabyanimalsandproducedmilktofeedthem.这些动物不同于以往所有的生物形态，因为他们能从体内生产出幼仔并给幼仔哺乳。1.Finallyabout2.6millionyearsagosomesmallcleveranimals,nowwithhandsandfeet,appearedandspreadallovertheearth.最后，大约260万年前，一些小巧聪明，长着手脚的动物出现了，他们散布在地球的各个地方。2.Thustheyhave,intheirturn,becomethemostimportantanimalsontheplanet.于是，他们接着成为这个行星上最重要的动物。3.Buttheyarenotlookingaftertheearthverywell.然而，他们对地球却不怎么在意，Par54.Theyareputtingtoomuchcarbondioxideintotheatmosphere,whichpreventsheatfromescapingfromtheearthintospace.他们把过多的二氧化碳释放到大气层中，这使得地球上的热不能释放到太空中去。5.Asaresultofthis,manyscientistsbelievetheearthmaybecometoohottoliveon.因此，许多科学家相信地球可能会变得太热而不适合生物生存。6.Sowhetherlifewillcontinueontheearthformillionsofyearstocomewilldependonwhetherthisproblemcanbesolved.所以，在未来的数百万年中，生命能否在地球上延续，取决于这个问题能否得到解决。主语从句主语从句一个句子在复合句中充当主语叫主语从句。一个句子在复合句中充当主语叫主语从句。常用引导词：常用引导词：连接词连接词：that(无词义无词义)whetherThathewillcomeandhelpusiscertain.Whetherwestayornotmakesnodifference.连接代词连接代词:who(ever)whomwhat(ever)which(ever)whoseWhowillgototheenergyconferenceisnotimportant.连接副词：连接副词：whenwherehowwhyWhenandwherethetestwillbegivenisnotdecided.1.引导主语从句的连词是不能省略的。引导主语从句的连词是不能省略的。Thattheearthisroundistrue2.That-从句作主语通常用从句作主语通常用it作先行词，而将作先行词，而将that-从句置于句末，例如：从句置于句末，例如：Itistruethattheearthisround.结构：结构：a.It+be+形容词形容词+that-从句从句Itisnecessarythat有必要有必要Itisimportantthat重要的是重要的是Itisobviousthat很明显很明显b.It+be+p.p.+that-从句从句Itisbelievedthat人们相信人们相信Itisknowntoallthat从所周知从所周知Ithasbeendecidedthat已决定已决定c.It+be+名词名词+that-从句从句Itiscommonknowledgethat是常识是常识Itisasurprisethat令人惊奇的是令人惊奇的是Itisafactthat事实是事实是d.It+不及物动词不及物动词+that-分句分句Itappearsthat似乎似乎Ithappensthat碰巧碰巧Itoccurredtomethat我突然想起我突然想起2.表示表示“是否是否”意义时，一般用意义时，一般用whether而不用而不用if引导主语从句，引导主语从句，Whethershewillcomeornotisstillaquestion3.有时可用形式主语有时可用形式主语it 代替主语从句：代替主语从句：e.g.It is still a question whether she will come or not.It has not been decided yet when they will start.4.无论主语从句有多长，一般做单数处理。无论主语从句有多长，一般做单数处理。e.g.Whenwewillstarthasnotbeendecidedyet.注意：注意：以以what开始的主语从句如果后面的表语是开始的主语从句如果后面的表语是复数名词，系动词用复数形式。复数名词，系动词用复数形式。Whathewantstobuyarethreebooksandtwopens.1.Itisobvioustothestudents_theyshouldgetwellpreparedfortheirfuture.A.asB.whichC.whetherD.that2._wantstostayinahotelhastopaytheirownway.A.AnyoneB.TheoneC.WhoeverD.Who练一练！练一练！3.Itisnotimmediatelyclear_thefinancialcrisiswillsoonbeover.A.sinceB.whatC.whenD.whether练一练！练一练！_leavestheroomlastoughttoturnoffthelights.A.AnyoneB.ThepersonC.WhoeverD.Who_thesportsmeetwillbehelddependsontheweather.A.WheneverB.IfC.WhetherD.That_isafactthatEnglishisbeingacceptedasaninternationallanguage.A.ThereB.ThisC.ThatD.It宾语从句宾语从句一个句子在复合句中充当宾语就叫宾语从句一个句子在复合句中充当宾语就叫宾语从句连接词连接词：that(无词义无词义)whetherife.g.Idontknowwhether(if)youarewillingtohelpme.连接代词：连接代词：what(ever)who(ever)whosewhich(ever)等等连接副词：连接副词：whenwherehowwhy等等特别提示特别提示1.由连接词由连接词that引导宾语从句时，引导宾语从句时，that在在句中不担任任何成分。句中不担任任何成分。Imgladthatyouhavepassedtheexam.2.有些词或词组如有些词或词组如hate,love,enjoy,dislike,feellike,appreciate,take(认为认为),relyon,dontmind等，习惯上后面跟等，习惯上后面跟it做形做形式宾语，再接宾语从句。式宾语，再接宾语从句。Itakeitthatyouwillagreewithus.3.在接复合宾语的句子中，为了保持句子在接复合宾语的句子中，为了保持句子平衡，用平衡，用it作形式宾语，而将从句放在作形式宾语，而将从句放在句尾。常带复合宾语的动词有：句尾。常带复合宾语的动词有：make/find/see/hear/feel/think等。等。IthinkitnecessarythatItakeplentyofwatereveryday.4.某些动词后的宾语从句常用虚拟语气，某些动词后的宾语从句常用虚拟语气，如如insist，order，request，suggest等。等。Isuggestedthatwe(should)startbefore5oclock.5.必须用必须用whether引导，引导，不可用不可用if:1).从句后有从句后有ornot时，不可用时，不可用if:Idontknowwhetherhewillcomeornot.2).介词宾语通常用介词宾语通常用whether引导引导:Itdependsonwhetherheiscomingornot.3).后接动词不定式时。后接动词不定式时。Canyoutellmewhethertogoortostay?4).discuss 后面的宾语从句解释为是否用whetherImagine you are in this situation,and discuss whether you should do something at once.5)主语从句放在句首Whetherwestayornotmakesnodifference.6）表语从句和同位语从句）表语从句和同位语从句Thequestioniswhetherwecangetthereontime.7)当当it做形式主语做形式主语whether/if都可引导主语从句都可引导主语从句Ithasntbeendecidedwhether/ifweshallattendthemeeting.6.用用who，whom,which(ever),whose,when,what(ever),where,why,how,whoever等关等关联词引导的联词引导的宾语从句宾语从句相当于特殊疑问句，相当于特殊疑问句，应注意句子语序要用应注意句子语序要用陈述语序陈述语序。Doyouknowhowoldheis?Iwanttoknowwhathehastoldyou.Shealwaysthinksofhowshecanworkwell.Shewillgivewhoeverneedshelpawarmsupport.凡需要帮助的人，她都会给予热凡需要帮助的人，她都会给予热情的支持。情的支持。7.think,believe,imagine,suppose等动词引等动词引起的否定性宾语从句中，要把上述主句中起的否定性宾语从句中，要把上述主句中的动词变为否定式。即将从句中的否定形的动词变为否定式。即将从句中的否定形式移到主句中。例如：式移到主句中。例如：Wedontthinkyouarehere.我们认为你不在这。我们认为你不在这。Idontbelievehewilldoso.我相信他不会这样做。我相信他不会这样做。如果主句主语为第一人称反意疑问句常与从如果主句主语为第一人称反意疑问句常与从句的主语和谓语保持一致；其他情况看主句的主语和谓语保持一致；其他情况看主句。例如：句。例如：IdontbelieveshehasbeentoAustralia,hasshe?我认为她没去澳大利亚，是吗？我认为她没去澳大利亚，是吗？Idontbelievethathecantranslatethisbook,?Shethinksthatherhusbandisthebestoneintheteam,？canhedoesntshe1.Idoubtif/whetherhewillpasstheexam.2.Idontdoubtthatwewillwinthematch.3.Doyoudoubtthathediditonhisown?doubt问题肯定句中用肯定句中用if/whether否定句中用否定句中用that疑定句中用疑定句中用that1.Idoubt_heistellingthetruth.2.Weneverdoubt_theplanwillbecarriedout.3.Doeshedoubt_youarefromAustria?4.Imdoubtful_hewillagreetothis.if/whetherthatthatif/whether宾语从句中的连接词宾语从句中的连接词that在以下三种情况下不在以下三种情况下不能省略：能省略：（1）当）当that 从句与另一名词性从句并列作宾从句与另一名词性从句并列作宾语时，第二个语时，第二个that不能省；不能省；（2）当）当that作介词宾语时，作介词宾语时，that不可省掉。不可省掉。（3）用）用it做形式宾语的宾语从句做形式宾语的宾语从句Everyone knew what happened and that she was worried.The reason lies in that she works harder than the others do.宾语从句1.Heasked_foraviolin（MET1992）A.didIpayhowmuchB.IpaidhowmuchC.howmuchdidIpayD.howmuchIpaid2Itisgenerallyconsideredunwisetogiveachild_heorshewants.(NMET1997)A.howeverB.whateverC.whicheverD.whenever3.Sheisverydeartous.Wehavebeenpreparedtodo_ittakestosaveherlife.A.whicheverB.however1.C.whateverD.whoever4.Thetruevalueoflifeisnotin_,but_.A.whichweget;whatgiveweB.whatweget;whatwegiveC.whichdoweget;whatdowegiveD.howweget;thatwegive5.HaveyouseenMarylately?Mybosswantstoknow_.A.howsheisgettingalongB.howisshegettingalongC.whatsheisgettingalongD.whatisshegettingalong6.Idontdoubt_hellcome.A.thatB.ifC.whatD.whether7.Doesanybodyknow_wewillhaveasportsmeetingthisweekendornot.A.ifB.whereC.whetherD.that结束语结束语谢谢大家聆听！谢谢大家聆听！44