初中英语状语从句专项练习题 23页

坡新资料推荐初中英语状语从句专项练习题()1Themeetingdidn'tstarteveryonewasthere.A.becauseB.untilC.whyD.if()2Theboytobedhismothercamein.A.wentnot;untilB.didn'tgo;afterC.went;untilD.didn'tgo;until()31won'tbelieveyouIhaveseenitwithmyowneyes.A.beforeB.untilC.afterD.when()4Hehomeshewassatisfiedhisansweryesterday.A.didn'tgo;until;withB.wasn'tgo;after;toC.doesn'tgo;before;withD.didn'tgo;until;to()5Hebackuntiltheworkdone.A.isn't;willbeB.isn't;isC.won'tbe;willbeD.won'tbe;is()6Theydidn'tstarttheworktheirteachercameback.A.untilB.whileC.assoonasD.if2()1TomwillcallmeassoonasheShanghai.A.arrivesB.willreachC.arrivesinD.getto()2I'msurehe'llcometoseemebeforeheBeijing.A.willleaveB.isleavingC.leaveD.leaves()31willtellhimthenewsassoonasheback.A.comeB.comesC.willcomeD.came3()1Tomhasgotawatch.Heitfortwoyears.Itbyhisfather.A.hasbought;wasboughtB.hasgot;isbought,C.wasbought;hasbought.D.hashad;wasbought()2Whenhegottothestation,thetrain.A.leftB.hadleftC.leavesD.hasleft()3Theboytoldhisfatherwhatheinthestreet.A.sawB.haveseenC.hadseenD.see()4WeTVwhenthetelephone.A.watched;wasringingB.werewatching;rangC.watch;ringsD.arewatching;rang()5Bytheendoflastterm,Itenbooks.A.hadfinishedreadingB.havefinishreadingC.hadfinishtoreadD.finishread4()11youforalongtime.Whereyou?A.didn'tsee;did;goB.didn'tsee;have;goneC.haven'tseen;have;beenD.haven'tseen;have;gone()2TomChinafor3years.A.hasbeenB.hasbeeninC.hasbeentoD.hasbeenat1/191/191/19\n城新资料推荐••••■•••••••••••••••••••••••••••••••••••••••••••••••・••••••••••••••••^5*1•••••••••••••・•••••••••••••••••••••••••••••••••••••••••・•()31won'tgotoseethefilmtonight,becauseImyticket.A.lostB.havelostC.willloseD.didn'tlose()4-Hello!MayIspeaktoBob?-Sorry,butheforamonth.A.hadbeenawayB.wasleftC.leftD.hasbeenaway()51himsinceIbegantoliveinthecity.A.knowB.haveknownC.knewD.willknow()6ZhaoLanalreadyinthisschoolfortwoyears.A.was;studyingB.will;studyC.has;studiedD.are;studying5()1Bettydidn'tgotoseethefilmyesterdayshewasill.A.becauseB.butC.untilD.if()2MayIsitnearerIcanseemoreclearly?A.asifB.sothatC.evenifD.so()3youworkhard,youwillcertainlysucceed.A.ThoughB.IfC.BecauseD.For()4hecametostudyintheuniversity,hehasmademuchprogressinthestudyofEnglish.A.WhileB.WhenC.SinceD.After()5Tdliketogoswimmingthewaterisnottoocold.A.forB.unlessC.ifD.whether6()1Therearemanyleaguemembersinclass2inClass4.A.both;andB.'so;thatC.either;orD.as;as()2-Doyouhaveabiglibrary?-No,wedon't.Atleast,notyours.A.asbigasB.asbigthanC.asbiggerthanD.biggeras()3SuzhouisnotbeautifulHangzhou.A.as;thanB.so;asC.even;thanD./;than()4Ironismoreusefulanyothermetal.A.asB.thanC.thenD.so7()11wanttoknowsheisgoingtoseeafilm.A.ifB.thatC.whatD.which()2Youaresuretopasstheexamyoustudyhard.A.ifB.thoughC.thatD.since()3I'llgotoseethefilmwithyouIhavetimethisevening.A.whetherB.soC.ifD.when()4youstudyharder;you'llneverpassthefinalexam.A.IfB.UntilC.UnlessD.Except8()1Althoughitwasraining,stillworkedinthefields.A.buttheyB.andtheyC.theyD.andyetthey()2therewereonlyfivesoldiersleftatthefront,theywent3/193/193/19\n城新资料推荐onfighting.A.Because;soB.If;andC.Though;butD.Though;/()3sheisveryold,shecanstillworkeighthoursaday.A.Because;soB.Though;butC.As;yetD.Though;yet9()1Pleaseanswerthequestioninaloudenoughvoicealltheclassmayhear.A.so,thatB.orC.inorderthatD.and()2LiftitupImayseeit.A.thoughB.sothatC.asD.than()31hurriedIwouldn'tbelateforclass.A.soB.sothatC.ifD.unless()4Weshouldgobybuswecangetthereearlier.A.assoonasB.whereC.inorderthatD.as10()1ThedictionaryissoexpensiveIcan'tbuyit.A.becauseB.whenC.thatD.if()21gottherelateIdidn'tseehim.A.too;toB.such;thatC.so;thatD.so;as()3Itishotintheroomwehavetogooutforawalk.A.such;thatB.so;thatC.as;asD.such;as()4Hehasaninterestingbookthatwewanttoreadit.A.soB.suchC.thesameD.as参考答案1.1-6BDBADA2.1-3CDB3.1-5DBCBA4.1-6CBBDBC5.1-5ABBCC6.1-4DABB7.1-4AACC8.1-3CDD9.1-4CBBC10.1-4CCBB情态动词表推测用法总结及专项练习1.can/could用于表推测的用法(1)从使用句型上看，can通常只用于否定句或疑问句，一般不用于肯定句，而could可用于肯定句、否定句和疑问句。两者没有时间上的差别，只是could比can更委婉，更不确定。如：3/193/193/19\n城新资料推荐Itcan't[couldn't]betrue.那不可能是真的。Whatcan[could]theybedoing?他们会在干什么呢？Wecouldgotherethissummer.今年夏天我们可能要去那儿。注：can有时也用于肯定句中表示推测，主要用于表示理论上的可能性(即从理论上看是可能的，但实际未必会发生)，或表示“有时”之意。如：Evenexperiencedteacherscanmakemistakes.即使是有经验的教师也可能出错。Shecanbeveryunpleasant.她有时很令人讨厌。(2)从时间关系看，对现在或将来情况作推测，后接动词原形；对正在进行的情况作推测，后接bedoing结构；对过去情况作推测,后接动词完成式。如：Hecouldhavegonehome.他可能已经回家了。Hecan't[couldn't]haveunderstood.他不可能理解了。Whydoesheknowthis?Can[Could]someonehavetoldhimaboutit?他怎么知道？会是哪个人告诉他了吗？3/193/193/19(3)“could+完成式”除表示对过去的推测外，还有以下重要用法：①表示过去没有实现的可能性，常译为“本来可以工如：Icouldhavelentyouthemoney.Whydidn5tyouaskme?我本2/192/197/19\n来可以借这笔钱给你的。你为什么不向我提出？②用来委婉地责备某人过去应该做某事而没有去做，常译为“本来应该”。如：Youcouldhavehelpedhim.你本来应该帮助他的。③表示“差点儿就要“。如：Icouldhavediedlaughing.我差点儿笑死了。2.may/might用于表推测的用法表示推测，两者都可用，只是might比may语气更不确定，表示的可能性更小。(1)在句型使用方面：两者均可用于肯定句和否定句，但用于疑问句时，may通常不用于句首，但可用于疑问句的句中(如特殊疑问句等)，而might尽管可以用于疑问句的句首，但不算普通，通常会改用其他句式(如用could等)。如：Hemay[might]knowtheanswer.他可能知道答案。Hemay[might]notbelieveyou.他可能不会相信你。Andwhomay[might]shebe?那么她会是哪一位呢？(2)从时间关系看，对现在或将来情况作推测，后接动词原形；对正在进行的情况作推测，后接bedoing结构；对过去情况作推测,2/192/197/19\n后接动词完成式。如：Hemay[might]tellhisw讦e.他也许会告诉他妻子。Hemay[might]bewritingaletter.他可能在写信。Shemay[might]havereaditinthepapers.她可能在报上己读到过此事。(3)“might+完成式”除表示对过去的推测外，还有以下重要用法：①表示过去某事可能发生而实际上却并没发生。如：Itwasreallyverydangerous.Imighthavekilledmyself.那真的是太危险了，我差点没命了。Alotofmendiedwhomighthavebeensaved.很多人本来可以获救的却死了。②表示委婉的批评或责备。如：Youmighthavemadegreaterprogress.你的进步本来可更大一些的。Youmightatleasthaveansweredmyletter.你至少可以回我一封信嘛。2.must表示推测的用法must表示很有把握的推测，其意为“一定会”“肯定会”，只用于肯2/192/197/19\n定句，一般不用于否定句或疑问句。表示对现在或未来的情况作推测,后接动词原形；表示对过去情况的推测，接动词完成式。如：Imustbethehappiestwomanonearth!我——定是世界上最幸福的女人了。No,hemustbelying.不，他一定在撒谎Hemusthavemistakenmymeaning.他一定误会了我的意思。2.shouldhavedone的用法shouldhavedone只用于谈论过去情况，主要有两个用法：一是用于推测过去己经发生的情况，二是用于指本该发生而实际上未发生的情况。如：Youshouldhavetoldmesobefore.你早就应该告诉我。Heshouldhavearrivedbynow.此时他本该到了。Lookatthetime!Weshouldhavebeenatthetheatretenminutesag。.瞧都什么时候了！十分钟前我们就该到戏院了。3.needhavedone的用法needhavedone结构主要用于否定句或疑问句，一般不用于肯定句。用于否定句时，表示本来不必做某事，但实际上却做了；用于疑问句时，用于询问某一过去动作的必要性。如：2/192/197/19\n蚁新资料推荐Youneedn'thavehurried.你当时实在不必那么匆忙。Sheneedn'thavecomeinperson—aletterwouldhavebeenenough.她本不必亲自来写封信来就足够了。Needyouhavepaidsomuch?你当时真须要付那么多钱吗？Needtheyhavesoldthefarm?他们那时非得把农场卖掉不可吗？历届NMET中表推测的情态动词的用法情态动词是中学英语学习中的一个重点和难点，也是高考的重点考察内容之一。其中表示推测用法的情态动词在近几年的高考中更是屡见不鲜。现结合近几年的高考题目，对表推测的情态动词的用法作一归纳，希望对各位考生会有所帮助:【考例】1.Naturally,afterItoldherwhattodo,mydaughtergoanddotheopposite!A.mayB.canC.mustD.should（2003年普通高等学校春季招生统一招生考试英语试题（安徽卷））【分析】Can,may,must都可用来表示“推测”，但侧重点各有不同:May常用来指”事实上的可能性”，而can则表示一种”理论上的可能性”例如:Therailwaysmaybeimproved.=ltispossiblethattherailwayswillbeimproved.=Perhaps/Maybe/Possiblytherailwayswillbeimproved.9/199/199/19\n蚁新资料推荐铁路可能会得到改进。（意味着已有具体的改进计划或方案。）Therailwayscanbeimproved.=ltispossiblefortherailwaystobeimproved.铁路可以得到改进。（意思是铁路还不完善，尚有问题存在。）理论上的可能性（can）比事实上的可能性（may）更弱。在一般的陈述句，can与sometimes几乎相同，表示一种偶然的可能性。比如：Evenexpertdriverscanmakemistakes.甚至是很熟练的驾驶员也可能会犯错。=Evenexpertdriverssometimesmakemistakes.=ltispossiblefortheexpertdriverstomakemistakes.因此，如果讲的是一种特殊情况，不是一般情况，就用may,试比较:MrReedlookspale.Hemaybeill.MrReedisinpoorhealth.Hecanbeillatanytime.Must指逻辑必然，作“想必”、“准是”、“一定”解，用来表示我们对某事有把握的推论或揣测。（考虑到迹象如此，再无另U的结论=ltseemscertainthat....）:Theymustbeverytirednow,fortheyhavebeenworkingthewholemorning.他们现在一定是非常累了，因为他们整个上午都在工作。9/199/199/19\n蚁新资料推荐析：填C.musto意思是“不出所料，当我告诉女儿要做的事时，她9/199/199/19\n\n及新资料推荐准会去做相反的事。”【考例】1、MarybeinParis.lsawherintownonlyafewminutesago.(NMET1994)A.mustn,tB.shouldn'tC.can,tD.maynot2>.-IsJohncomingbytrain?(NMET2002Tianjing)-Heshould,buthenot.Helikesdrivinghiscar.A.mustB.canC.needD.may【分析】May用于否定时，not不是否定may,而是否定句中的动词，这一点与can不同，试比较：Hemaynotknowthetruth.他可能不知道事情的真相。(=ltispossiblethathedidn'tknowthetruth.)Hecannotknowthetruth.他不可能知道事情的真相。must表示推测的这种用法通常用在肯定句中，在疑问句中常用can(可能)，在否定句中常用can't(不可能，不会是),而不用mustn't。例如：一Somebodyisknockingatthedoor.Whocanitbe?ItmustbeWangHong.No,Itcan'tbeWangHong,becausesheleftforShanghaithismorning.一有人在敲门。会是谁呢？一定是王红。…不，不会是王红，因为她今天早晨就动身去上海了。因而Youmustbejoking.在意义上相当于Youcan'tbeserious.11/1911/1911/19\n及新资料推荐析：1、填C。意思是“玛丽不可能在巴黎。几分钟前我还看见她在镇上。2、填Do意思是”••约翰会坐火车来吗？”应该会，但他可能不会。他喜欢开车。”【考例】1.—Iheardtheywentskiinginthemountainslastwinter.(NMET2002Beijing)-Ittruebecausetherewaslittlesnowthere.A.maynotbeB.won*tbeC.couldn'tbeD.mustn*tbe【分析】Could,might表示过去的可能性。Ithoughtitmightbetrue.我本认为那是真的。Hecouldbeveryunreasonable,他有时可能毫不讲理。析：填C。它是对去年冬天所发生的事进行评价。【考例】1.-AreyoucomingtoJeff'sparty?(NMET2000)-Pmnotsure.lgototheconcertinstead.A.mustB.wouldC.shouldD.might2.—Look!Thecloudsaregathering.—Yes.rmafraiditbepouringdownsoon.A,canB,mustC,shouldD,might【分析】could和might表示现在的情况时，更带有不肯定性和慎重味道，构成礼貌或婉转说法，包含或许的意思:A:lwonderwhereTomis.B:Hemay/might/couldbeinthelibrary.(Perhapsheisinthelibrary.)因此在wonder,fear,beafraid等后接的从句中，通常用11/1911/1911/19\n••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••・••^5*1••••••••••••••••••••••••••••••••••••••••••••••••••••・••・•may/might/could,表达一种探询的观点：Iwasafraidyoumightbeoutofsorts.我怕你可能心情不痛快。假设性的可能和试探性的可能，也用could和might：Ourteammightstillwintherace.（可以意译为：Itispossible,thoughunlikely,that）析：1、2均填D.might【考例】Mr.Bushisontimeforeverything.Howitbethathewaslatefortheopeningceremony?A.canB.shouldC.mayD.must（2001年上海普通高校春季招生考试试卷）【分析】表示推测的may通常不用于一般疑问句，而要用can代替。Can用于一般疑问句时，还可表示惊讶或怀疑，意思是"（到底）可能有这样的事吗？"，比如：“Thereisthedoorbell.,J,,Whocanitbeatthistimeofday?”有人按门铃。"”这个时候到底会是谁呢？”Must也偶尔用于疑问句：Musttherebesomegoodreasonforthedelay?这个问句设想的是一个肯定的回答，可以解释为“Doestherehavetobesomegoodreason?”may可用于特殊疑问句或wh•从句，意思是"（到底）是…“、”不知是否…”：12/1912/1912/19\nIwonderwhatitmaymean.我不知道这究竟是什么意思。Howoldmayhisfatherbe?他父亲到底有多大年纪？（比Howold12/1912/1912/19\n城新资料推荐ishisfather?委婉的说法。)析：填1、A.can.(布什先生做什么事都很按时。他怎么可能会在开幕式上迟到呢？)【考例】1.SorryTmlate.Ihaveturnedoffthealarmclockandgonebacktosleepagain.(2000年普通高等学校春季招生考试(北京、安徽卷)A.mightB.shouldC.canD.will2.-Therewerealreadyfivepeopleinthecarbuttheymanagedtotakemeaswell.-It_acomfortablejourney.(NMET95)A.can'tbeB.shouldn'tbeC.mustn'thavebeenD.couldn'thavebeen【分析】“情态动词have+-ed分词”结构可以表示对已发生的事情进行推测，就表示的可能性程度而言，must最大，could其次，may更次之，might最小。must+have+・ed分词：用于肯定句，表示推测过去某事”肯定,一定，准是”发生了。其否定形式为：can't/couldn'thavev・ed,表示过去不可能发生某事。may(might)+have+-ed分词：用于肯定句和其他否定句，表示对已发生事情的不肯定的推测，意为“可能,大概”，其中might较may语气更弱，把握更小。Can/could用于否14/1914/1914/19\n城新资料推荐定或疑问句中，表示对过去发生的事件的“怀疑或不肯定”。could比can更表示说话人语气的不肯定。例如：Imailedthatletteraweekago.Hemusthavereceivedit.我一周前就发出了那封信，想必他一定收到了。Ican'tfindmykeys.Imay/mighthaveleftthemattheschoolyesterday.Jackcan'thavearrivedyet,otherwisehewouldhavetelephonedme.（上海1997）Itcouldn*thavebeenMr.Smith.HehasgonetoChina.不太可自甘是史密斯先生。他已去了中国。另外，注意may不可用于疑问句，它的这种功能已为can所取代。例如Cantheyhavemissedthebus?的答句是：Yes,theymayhavedone,而不是Yes,theycanhavedone.这一点要注意。Must偶尔也能用于否定句：Hisabsencemustnothavebeennoticed.此句和Hisabsencecan'thavebeennoticed.的意思是一样的。许多评论者认为这类句子是不可能成立的，但它们正在为越我来越多的人所接受和使用，在美国英语中尤其如此。对正在发生的事情进行推测，则采用“情态动词+be+现在分词”结构,其中情态动词的区别与上相同。析：答案A、D。can通常不用于肯定句表猜测；"should+have+-ed14/1914/1914/19\n城新资料推荐分词”表示“过去本来应该做……”，但实际上没有做，意思是“本该♦….”，带有责备口气：lwasreallyanxiousaboutyou.Youshouldn'thaveleftwithoutaword.14/1914/1914/19\n及新资料推荐(NMET2001)；"will+have+・ed分词”只是将来完成时的一种形式。【考例】l.lt'snearlyseveno'clock.Jackbehereatanymoment.(NMET95)A.mustB.needC.shouldD.can【分析】should(oughtto)表示很可能、预期的意思，指一种尝试性推论,可认为是must的语气较弱的对应词，意思是”应该会、一定。。o吧”。试比较：Ourguestsmustbehomebynow.(1amcertain')我们的客人现在一定到家了。(根据他们动身的时间、路程远近、速度等具体条件,我能断定/肯定他们现在已经到家了。)Ourguestsshould(oughtto)behomebynow.('Theyprobablyare,butlJmnotcertain.)我们的客人现在该到家了。(含义是我想他们很可能到家了，但我不能肯定”)与must不同还在于它常常表示将来：-WhencanIcomeforthephotos?lneedthemtomorrowafternoon.-Theybereadyby12:00.(NMET1998)A.canB.shouldC.mightD.need表示不太可能可用shouldn^oughtn^to):16/1916/1916/19\n及新资料推荐Thereshouldn't(oughtn'tto)beanydifficulties.不该有任何困难。析：填C。意思是”将近七点了。杰克很可能随时会到。”另外,在近几年的NMET中，对情态动词及其它语法项目的考查均放到一定的语境中进行,要求考生利用所学英语各项基础知识进行初步的语言运用，而不再是单纯的语法知识题和短语题。这类试题往往通过题干的其他部分或附加句子提供某个信息，然后让考生根据这个信息进行合理推理，产生新的想法和认识。因此，在做这类题时，除要熟悉所考查的语法规则外，还要认真分析句子的结构，注意抓住关键词，分析上下文的逻辑关系。不能单凭语法规则做题。巩固练习1.Michael_beapoliceman,forhe'smuchtooshort.A.need】B.can'tC.shouldD.may2・Johnny,you_playwiththeknife.You_hurtyouself.A.wontcanlB.mustnl,mayC.shouldn't,mustD.canft,shouldn't3.Peter_comewithustonight,buttakenheisn'tverysureyet.A.canB.mayC.willD.must4.Putonmoreclothes.You_betakenfeelingcoldwithonlyashirton.A.mustB.canC.couldD.would5.1fsnearlyseveno'clockJack_behereatanymoment.A.mustB.needC.shouldD.can1.1didn'thearthephone.I_asleep.16/1916/1916/19\n鼓新资料推荐A.mustbeB.musthavebeenC.shouldbeD.shouldhavebeen7.Jack_yet,otherwisehewouldhavetelephonedme.A.mustn'thavearrivedB.shouldn^havearrivedC.can'thavearrivedD.neednothavearrived8."therewerealreadyfivepeopleinthecarbuttheymanagedtotakemeaswell.-It_acomfortablejourney.A.canlbeB.shouldn'tbeC.mustn'thavebeenD.couldnfthavebeen9.He_youmorehelp,eventhoughhewasverybusy.A.mighthavegivenB.mightgiveC.mayhavegivenD.maygivelO.YesterdayJanewaookedawayfromthediscussion.Otherwise,she—somethingthewouldregretlater.A.hadsaidB.saidC.mightsayD.mighthavesaid11.Therewasplentyoftime.She_.A.mustn'thavehurriedB.needn'thavehurriedC.shouldhavewrittenitoutD.couldn11havehurried12.Tomoughtnotto_meyoursecret,butbemeantnoharm.A.havetoldB.tellC.betellingD.haven'ttold13.1toldSallyhowtogetthere,butperhapsI_forher.A.hadtowirteitoutB.musthavewrittenitoutC.shouldhavewrittenitoutD.oughttowriteitout13.2fyouhadworkedharder,you—.A.wouldsucceedB.hadsucceededC.shouldsucceedD.wouldhave18/1918/1918/19\n鼓新资料推荐succeeded15."Ifhe—,he_thatfood,"luckilyhewsasenttothehospitalimmediately.A.waswarned;wouldnottakeB.hadbeenwarmed;hadnottakenC.wouldbewarned;hadnottakenD.wouldhavebeenwarned;hadnottaken16.-IstayedatahotelwhileinNewYork.-Oh,didyou?You_withBarbara.A.couldhavestayedB.couldstayC.wouldstayD.musthavestayed17.SorryI'mlate.I_haveturnedoffthealarmandgonebacktosleepagain.A.mightB.shouldC.canD.will18.—ShallItellJohnaboutit?-Noyou—.Fvetoldhimalready.A.needn*tB.wouldnlC.mustn'tD.shouldnt19.Thenewairoprt_iftheyhadnotstoppedworkingonit.A.wouldcompleteB.hadbeencompletedC.hadcompletedD.wouldhavebeencompleted20.1didn'tseeherinthemeeting-roomthismorning.Sheatthemeeting.A.mustn'thavespokenB.shouldn'thavespokenC.needn'thavespokenD.couldn*thavespoken21.Thatyoungmanhasmadesomuchnoisethathe_nothavebeenallowedtoattendtheconcert.18/1918/1918/19\n••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••・••^5*1••••••••••••••••••••••••••••••••••••••••••••••••••••・••・•A.couldB.mustC.wouldD.should22.Susan_writtenareportlikethis.A.canhaveB.mustn'thaveD.canlhaveD.oughttonothave23.Therewasdalotoffunatyesterday'sparty.You_come,butwhydidn'tyou?A.musthaveB.shouldC.needhaveD.oughttohave答案及难点解析1LB2.Bmustn't表示“禁止”,may表示“不可能”3.Bcan表示“理论上的可能、普遍性的可能、当然的可能，并非说话人主观认为可能，即并非猜测“，故不可选Ao4.A5.Catanymoment/minute意为“随时，马上6.B由句中的时态可知是在对过去的事件进行推测，故用情态动词+havedone。7.C由otherwise…一句可知说话人对Jack没有来持确定的态度。除所给答案外，A也正确。8.D与7题相似，C也是正确的，意为“肯定不舒服”。9.Amay不可表示过去的事。10.D11.B表示“当时本没必要那么匆忙”。12.A13.C14.D15.B16.A二人相遇的可能性不大。17.A18.A19.D对过去情况的虚拟假设，注意要用被动语态。20.D21.D22.C据常识可知是在对过去的事进行推测。23.D19/1919/1919/19