会计学shallmust,mustn’tusedto和would的区别(qūbié)巩固练习Must+do/bedoing可以对现在(xiànzài)、现在(xiànzài)进行的情况进行肯定的推测Must+havedone表示对过去已经发生的行为(xíngwéi)进行推测，意为“想必/准是/一定作了某事”。NOTICEcan后跟动词原形，表示(biǎoshì)小、对现在情况的否定和疑问推测can/could+havedone表示对过去的行为(xíngwéi)的怀疑和不肯定，通常用在否定句和疑问句中。may/might后跟动词原形，表示对现在(xiànzài)情况的推测。may/might+havedone表示对过去已发生行为的推测，意为“也许/或许/已经…”。一般只用语肯定句和否定句中，不用与疑问句。might比may更委婉、含蓄和不肯定。should/oughtto表示(biǎoshì)推测，意为“理应，应该”。巩固练习5.---Youmaylaugh,butI’vebeenthinkingofbecomingavegetarian.---Oh,you____beoutofyourmind.Youwillbehungryallthetime.A.willB.mayC.mustD.should6.---Iwonderwhytheyarelate?---They_____thetrain.can’thavemissedB.couldmissC.musthavemissedD.mightmiss7.---Showmeyourpermit,please!---Oh,it’snotinmypocket.It______.A.mightfalloutB.couldfalloutC.shouldhavefallenoutD.musthavefallenout7.---HasMikestarted?Hesaidhewouldjoinintheparty.---He____.Heisamanofkeepinghisword.A.couldhaveleftB.musthaveleftC.can’tcomeD.won’tbecoming8.Everythinghastwosides.Beautifulsongs,sometimes,___bejustnoisetoothers.mustB.mayC.shouldD.could9.---Therewerealreadyfivepeopleinthecar,buttheymanagedtotakemeaswell.---It___acomfortablejourney.A.can’tbeB.mustn’thavebeenC.shouldbeD.couldn’thavebeen10.Chinesemusthavethelargestnumberofspeakers,____.A.mustn’ttheyB.haven’ttheyC.don’ttheyD.didn’ttheycould(不用can)+havedone,在肯定句中表示“本来能够(nénggòu)…而没能…”，具有婉转的批评和责备之意。should/oughtto+havedone用于肯定句时，表示“本该(běnɡāi)做某事而实际上没做”，用于否定句时，则表示“不该做的事反而做了”。might（不用may）+havedone表示“本来可能…”，但实际上没有发生的事。另外(lìnɡwài)，还可表示“本来应该或可以做某事”之意，含有轻微的责备语气。needn’t+havedone表示(biǎoshì)做了本来不必去做的事。巩固练习4.Asitturnedouttobeasmallhouseparty,we____soformally.needn’tdressB.didn’thavetodressupC.MightnothavedressedupD.needn’thavedressedup5.I’mrathersurprisedyouhaven’treportedhimtoyourteacher.Inmyopinion,you___thisassoonasyoufoundouthewascheating.musthavedoneB.mighthavedoneC.shouldhavedoneD.couldhavedone1.canmot…too/enough表示“无论怎么(zěnme)…也不（过分）…”，“越…越好”。例如：Youcannotbetoocareful.你越小心越好。YoucannotrememberenoughEnglishwords.你记的英语单词越越好。2