高中英语必修3-unit4-Grammarppt课件 30页

Unit4Discoveringusefulstructures\nNounclausesasthesubject\n4.Tofindyourwaycanbeaproblem.Whatdoestheunderlinedpartserveasineachsentence?3.Smokingisbadforyou.2.Youareastudent.5.“Howdoyoudo?”isagreeting.6.Itiscertainthatweshallbelate.subject1.Beijingisourcapital.\nReadthesentencesfromthetextandpayattentiontotheunderlinedparts.1.Whatitwastobecomewasuncertainuntilbetween4.5and3.8billionyearsago…2.…itwasnotclearwhethertheshapewouldlastornot.3.Whatisevenmoreimportantisthatastheearthcooleddown,waterbegantoappearonitssurface.4.Whatmanyscientistsbelieveisthatthecontinuedpresence…5.Whytheysuddenlydisappearedstillremainsamystery.\n主语从句是在复合句中充当主语的从句，其功同名词一样。为了避免头重脚轻，常用it作形式主语,而把真正主语放在句子末尾。Howthebookwillselldependsonitsauthor.Thatheisthebeststudentintheclassisobvious.=Itisobviousthatheisthebeststudentintheclass.主语从句\n引导主语从句的关联词有三类：(1)从属连词thatThattheyweretruesisterswasclearfromthefacialresemblancebetweenthem.(2)从属连词whetherWhetherhe’llcomehereisn’tclear.\n(3)连接代词who,whom,whose,what,which,whoever,whatever,whichever连接副词where,when,how,whyWhatshedidisnotyetknown.Howthishappenedisnotcleartoanyone.Whoevercomesiswelcome.\nThathefinishedwritingthecompositioninsuchashorttimesurprisedusall.Howhebecameagreatscientistisknowntousall.Whothewatchbelongstoisunknown.主语从句用陈述语序关联词位于句首,不能省略\n1.在主语从句中，谓语动词一般用单数。Whateverhesaysisofnoimportance.Whoeversaysthisiswrong.但谓语动词用单数还是复数，不可一概而论，而要视句子的意义而定：WhatIneedismoney.WhatIneedarebooks.\n2.what与that在引导主语从句时的区别what引导主语从句时在从句中充当句子成分，如主语、宾语、表语，而that则不然。Whatyousaidyesterdayisright.Thatsheisstillaliveisaconsolation.\n3.It作形式主语和it引导强调句的比较It作形式主语代替主语从句，主要是为了平衡句子结构，主语从句的连接词没有变化。而it引导的强调句则是对句子某一部分进行强调，无论强调的是什么成分，都可用连词that。被强调部分指人是也可用who/whom。Itisstillamysterywhatcausedtheaccident.Itisamysterythathisdeathremained.\nwhether引导主语从句时，常置于句首（此时whether不能用if代替），也有后移的用法（此时whether可以用if代替）Whethertheywillcomeisnotyetknown.Itisnotyetknownwhether/iftheywillgothere.4.whether与if\nwhether和if的区别还有：1.引导表语从句用whetherThequestioniswhetheryoushouldacceptit.2.whether可以引导从句作介词的宾语I’mnotinterestedinwhetherthey’llgoornot.Itdependsonwhetherwehavegotenoughmoney.3.whether可以直接跟动词不定式连用Ididn’tknowwhethertolaughortocry.Shehasn’tdecidedwhethertogoornot.\n(1)Itis＋名词＋从句Itisafactthat…事实是……Itisanhonorthat……非常荣幸Itiscommonknowledgethat……是常识(2)Itis＋形容词＋从句Itisnaturalthat…很自然……Itisstrangethat…奇怪的是……用it作形式主语的结构\n(3)Itis＋不及物动词＋从句Itseemsthat…似乎……Ithappenedthat…碰巧……Itappearsthat…似乎……(4)It＋过去分词＋从句Itisreportedthat…据报道……Ithasbeenprovedthat…已证实……Itissaidthat…据说……\n_____weunderstandthingshasalottodowithwhatwefeel.【解析】句意：我们如何理解事情与我们所感受的有很大关系。根据句意可知，主语从句缺少方式状语，因此填how。典型例题How\n_______makesthebooksoextraordinaryisthecreativeimaginationofthewriter.【解析】句意：使得这本书如此不同凡响的是作者创造性的想象力。句子的主语是一个从句，空处是引导主语从句的连词，这个连词要同时在主语从句中充当主语，填what。What\nItdoesn’tmatter________youturnrightorleftatthecrossing—bothroadsleadtothepark.解析：考查whether引导主语从句，it作形式主语。引导主语从句时，只能用whether，不能用if。whether\nItsuddenlyoccurredtohim_____hehadlefthiskeysintheoffice.解析：此句是occurtosb.表示“想到、想起”的典型句式，that这里是做引导主语从句的连接词。that\nAsmanyasfivecoursesareprovided,andyouarefreetochoose_________suitsyoubest.解析：考查名词性从句。所填词引导的从句做动词choose的宾语，引导词在从句中做主语。填whichever。whichever\nItisstillunderdiscussion_________theoldbusstationshouldbereplacedwithamodernhotelornot.解析：根据句意：旧车站是否被一个现代化旅馆代替还在讨论之中。后面出现了ornot，故填whether。whether\n________BarbaraJonesofferstoherfansishonestyandhappiness.解析：What引导的是主语从句，在从句中充当offers的宾语。句意为：芭芭拉琼斯为她的粉丝所提供的是诚实和快乐。What\nBeforeaproblemcanbesolved,itmustbeobvious______theproblemitselfis.解析：分析句子结构可知，本句为before引导的时间状语从句，在从句中it为形式主语，真正的主语为“_____theproblemitselfis”，在此主语从句中又缺少表语，即用what引导。what\n1.______youdon’tlikehimisnoneofmybusiness.2.______hesaidatthemeetingastonishedeverybodypresent.3.Onmywayhomeinthestreet,Isawalady______Ithoughtwasyouraunt.PracticeThatWhatwho\n4.TheForeignMinistersaid,“______isourhopethatthetwosideswillworkto-wardspeace.”5.Wecannotexplain_____quiteanumberofinsects,birdsandotheranimalsaredyingout.6.Does______matterifhecan’tfinishthejobontime?Itwhyit\n7.________thesportsmeetwillbehelddependsontheweather.8._______beatXiaoWangblackandblueisnotknown.9.______wecan’tgetseemsbetterthan______wehave.WhetherWhoWhatWhat\n10.________makesmistakesmustcorrectthem.11.Itworriedherabit______herhairwasturninggrey.12.Whenandwhyhecamehere______notknownyet.Whoeverthatis\n1.A:Thatlighttravelsinstraightlinesisknowntoall.B:_____________________thatlighttravelsinstraightlines.2.A:Whentheplaneistotakeoffhasnotbeenannounced.B:___________________________whentheplaneistotakeoff.It’sknowntoallIthasnotbeenannounced转换句子\n3.A:Itisamysterytomewhichofthemwonthegoldmedal.B:Whichofthemwonthegoldmedal_________________tome.4.A:Hehasn’ttoldusthereasonforhisbeinglateagain.B:___________________________hasnotbeentold.isamysteryWhyhewaslateagain\n1.Reviewnounclausesastheobject,predicativeandsubject.2.Finishtheexercisesin“Discoveringusefulstructures”.3.FinishtheexercisesinUsingstructureofWorkbook.Homework