。語法：情態(tài)動詞must、haveto 和havegotto情態(tài)動詞 must和haveto 都有“必須”的含義，它們的用法如下：（一）、must“必須”、“應該”的用法:1.must 表示“必須”、“應該”。例如：①Wemustprotectourenvironment.( 我們必須保護環(huán)境。）②Everyonemustobeytherule. （人人必須遵守制度。）2.must的否定形式mustnot表示“不應該”、“禁止”、“不準”。語氣比較強烈。例如：①Youmustn’tspeaklikethat.( 你不應該像那樣講話。）②Youmustn’tbelateforschool. （你不應該上學遲到。）3.在回答must的問句時，肯定形式用must來回答，但否定形式用needn’t或don’thaveto來回答。而不用mustn’t來回答。例如：①——MustIbehomebefore8o ’clock?(8 點之前我必須回家嗎？ )——Yes,youmust. No, youneedn’t./No, youdon’thaveto.（是，你必須。） （不，你不必。）4.must還可表示推測，意思是“一定”、“必定”，一般只用于肯定句中。分三種情況：）對于現(xiàn)在狀態(tài)的推測，我們用：must+v.（狀態(tài)動詞或系動詞），例如：①Hemustbeathome.( 他準在家里。）②Theremustbesomechildrenintheroom. （房間里準有些孩子。））對于現(xiàn)在動作的推測，我們用：must+be+doing（行為動詞），例如：①Theymustbecleaningtheirroom.( 他們準是在打掃房間。）HemustbewatchingTV.（他準是在看電視。）3.）對于過去事實的推測，我們用： must+have+過去分詞，例如 :①Itmusthaverainedlastnight.( 昨晚準是下雨了。）②Ididn ’thearthephone.Imusthavebeenasleep. （我沒有聽到電話，我準是睡著了。）（二）、haveto 表示“必須”、“不得不”，例如：①Hehastostayinbedfor3or4days.( 他必須臥床休息三四天。 ）②Wewillhavetogetupearlytomorrow. （明天我們必須早起。）（三）、havegotto 是haveto 的口語形式。例如：①I’vegottoleaveforNanjing.( 我不得不去南京。 )*Must與haveto 的區(qū)別：must表示的是說話人的主觀看法，而 haveto則表示的是客觀需要。 Must一般只有現(xiàn)在時，而 haveto 有更多的形式。。1。①Imustgonow.(主觀看法)②Mymotherisill,soIhavetogonow.(客觀需要)*Haveto與havegotto的區(qū)別：havegotto雖然是haveto的口語形式，但二者在用法上有嚴格的區(qū)別：haveto的前面還可以用情態(tài)動詞或助動詞，而havegotto卻不可以；haveto的否定形式為don’t/doesn’t/didn’t+haveto,疑問式為Do/Does/Did+主語+haveto??而havegotto的否定形式是在have后加not,疑問式把have提前。例如：①Wedon’thavetogohome.①Doyouhavetogohome?②Wehaven’tgottogohome.②Haveyougottogohome?一、.Fillintheblanksusinghaveto,havegotto,must,should,oughtto,hadbetter.1.You_____________notgetdownuntilthebushasstopped.2.They_____________beencouragedtospeakEnglishafterclass.3.Youoften_____________waitalongtimeforabus.4.We_____________goandseeMarytomorrow,butIdon’tthinkwewill.5.I_____________notmissmytrain.6.Whentraveling,you_____________takecareofyourhealth.7.Insomepartsoftheworld,you_____________boilthewaterbeforedrinkingit.8.Ifyouhaveastomachpain,you_____________drinkhotweaktea.9.You_____________notswimimmediatelyafteraheavemeal.10.You_____________notwakemeupwhenyoucomein.11.He_____________beill,forhelookssopale.12.You_____________nothavegivenhimthemoney.13.It’sgettinglate.IamafraidI_____________go.二、Choosethebestanswer.1.----MustIdoitnow?-----No,you_______.A.needn’tB.don’thavetoC.mustn’tD.AorB2.It’snearlyseveno’clock.Jack______behereatanytime.A.mustB.needCshouldDcan.3.------WhencanIcomeforthesephotos?Ineedthemtomorrowafternoon.。2。-------They ____bereadyby12:00.A. canB. shouldC. mightD.need4.Sorry,I ’mlate.I________haveturnedoffthealarmo ’clockandgonebacktosleepagain. A.might B.should C.can D.will5.ItoldSallyhowtogetthere,butperhapsI________forher.A.hadtowriteitout B.musthavewrittenitoutC.shouldhavewrittenitout D.oughttowriteitout6.Jenny________havekeptherword.Iwonderwhyshechangedhermind.A.must B.should C.need D.would7.Tomoughtnotto________meyoursecret,buthemeantnoharm.A.havetold B.tell C.betelling D.havingtold8.Sir,you________besittinginthewaitingroom.Itisforwomenandchildrenonly.A.oughtn ’tto B.can ’tbe C.won ’tD.needn’t9.Ifyoureallywantyourselftobeingoodhealth,youmust______always______somuch. A.not,besmoking B.not,havesmokedC.not,tosmoke D.benot,smoking10.Ididn ’thearthephone,I________asleep.A.mustbe B. musthavebeen C. shouldbe D. should havebeen11.I wasreally anxious about you.You________homewithout aword.A.mustn’tleave B.shouldn ’thaveleftC.couldn ’thaveleft D.needn ’tleave12.You’dbettergoatonce,_________you?A.shouldn ’tB.wouldn ’tC.hadn ’tD.couldn ’t13.Sheoughttobepraised,_________?A.oughtshe B.sheought C.oughtn ’tshe D.sheoughtn ’t14.He_________gotherebytrain.A.oughtn ’ttoB.oughtn ’tC.oughttonotD.didn ’toughtto15.--------Look,it_________beMr.Wang.------------No,it_________behim.Hehasgoneabroad.A.may;mustn’tB.must;maynotC.must;can’tD.can;maynot三、Correctthemistakeineachsentence:1.Youhavebetterhurryup.2.Thetaxi