2019年高考英语试题分类汇编 情态动词、虚拟语气.doc

2019年高考英语试题分类汇编 情态动词、虚拟语气05全国Tom, youleave all your clothes on the floor like this!A.wouldntB.mustntC.needntD.may not答案B考点考查情态动词。解析wouldnt用以提示客气的请求；mustnt表示禁止, 不允许；neednt表示没必要；may not表示不可以。根据语境要求Tom不许把衣服放在地板上。05全国John, look at the time.you play the piano at such a late hour?A.Must B.Can C.MayD.Need答案A考点本题考查情态动词的用法。解析must在此处显示出说话人的不快, 有 “难道非要”的意思。05北京Hehave pleted his work; otherwise, he wouldnt be enjoying himself by the seaside.A.should B.must C.wouldntD.cant答案B考点考查情态动词表猜测的用法。解析由句意 “他一定是已经完成工作了；否则, 他就不会在海边玩得那么高兴。”可知是对过去发生事情的肯定推测。05上海Therebe any difficulty about passing the road test since you have practised a lot in the driving school.A.mustntB.shant C.shouldntD.neednt答案C考点本题考查情态动词的用法。解析句意为：因为你在驾校已经训练了这么多, 通过路考一定没有什么困难。本句中表达出劝慰对方的语气。mustnt表示 “禁止, 不允许”, 表示警告或命令; shant表示 “将不会”；shouldnt表示据情况推测 “理应”；neednt表示 “不必”。05天津Ihave been more than six years old when the accident happened.A. shouldntB.couldnt C.mustntD.neednt答案B考点考查对过去发生的情况的推测。解析couldnt have done是对过去发生情况的否定推测, 其肯定形式同样是对过去发生情况的推测, 意为 “可能已”。shouldnt have done本来不应该, 但实际已经；neednt have done本来不需要, 但实际上已经；must表示推测时, 只用在肯定句中。故选B项。05辽宁This cake is very sweet. Youa lot of sugar in it.A.should put B.could have put C.might putD.must have put答案D考点本题考查情态动词的用法。解析句意为：这蛋糕, 非常甜。你一定放了许多糖在里面。05浙江The World Wide Web is sometimes jokingly called the World Wide Wait because itbe very slow.A.should B.must C.willD.can答案D考点本题考查情态动词的用法。解析此处表达一种可能性, 要用can, 其他三项都表示主观情态。should应该, 义务, must必须, 一定, will将会, 都与句意不符。05福建Catherine, I have cleaned the room for you.Thanks.Youit. I could manage it myself.A.neednt doB.neednt have doneC.mustnt do D.shouldnt have done答案B考点考查情态动词的完成式和一般式的区别。解析neednt do不需要做；mustnt禁止做, 都用于现在的动作；neednt have done表示做了本来不必去做的事；shouldnt have done是本不该做却做某事。05湖南Lucy doesnt mind lending you her dictionary.She.I have already borrowed one.A.cant B.mustnt C.needntD.shouldnt答案C考点考查情态动词的辨析。解析根据后面的句子 “Ive already borrowed one”说明她没必要借字典给我了, 故选C项。05湖北Do you know where David is? I couldnt find him anywhere.Well, hehave gone farhis coats still here.A.shouldntB.mustnt C.cantD.wouldnt答案C考点本题考查情态动词的用法。解析由句意可知, “他肯定没走远”, 此处是对过去的否定推测, 而且语气最强, 故用cant have done。05江苏Dont you think it necessary that heto Miami but to New York?I agree, but the problem ishe has refused to.A.will not be sent;that B.not be sent;thatC.should not be sent;whatD.should not send;what答案B考点本题考查虚拟语气中情态动词的用法。解析not be sent是虚拟语气, 相当于should not be sent。05山东He paid for a seat, when he _ have entered free.A. couldB. wouldC. mustD. need答案A考点本题考查虚拟语气中情态动词的用法。解析根据题干可看出此处句意为 “他本来可以免费入场”, 因此应用could have done。05湖北If Iplan to do anything I wanted to, Id like to go to Tibet and travel through as much of it as possible.A.would B.could C.had toD.ought to答案B考点本题考查情态动词的用法。解析句意为：如果我能计划做任何想做的事, 我想去西藏尽可能地游览一番。观察一下句中的时态, 因为都是过去时, 句意表示与现在事实相反的虚拟语气, 因此此处应用情态动词的过去时, 表示的意思是 “假如我们现在能够”, could表示不存在的可能性。05重庆I was on the highway when this car went past followed by a police car.They at least 150 kilometers an hour.A.should have been doing B.must have been doing C.could have doneD.would have done答案B考点本题考查情态动词的用法。解析must have done用于肯定句中, 表示对过去事情的推测, 意为 “想必是, 一定是”。否定句、疑问句中对过去情况的推测, 要用can/could have done的形式。05山东He paid for a seat, however, hehave entered free.A.could B.would C.mustD.need答案A考点本题考查情态动词的用法。解析paid暗示时间上指的是过去, could have done用于肯定句中表示本可以做而未做的事情；肯定句中不用need have done; must have done与语境不吻合。据题干可看出此处句意为 “他本来可以免费入场”, 因此应用could have done。05江西Tom is never late for work.Why is he absent today?Somethingto him.A.must happen B.should have happenedC.could have happened D.must have happened答案D考点本题考查情态动词的用法。解析must have done的意思是 “一定发生了某事”。由对话所提供的情景可知：汤姆从不迟到, 所以他 “一定有事”。因此D项正确。05安徽Helengo on the trip with us, but she isnt quite sure yet.A.shall B.must C.may D.can答案C考点此题考查情态动词的用法。解析may表示一种可能性。如果没有具体的语境的话, B、D两项也可以选, 但是意思就不同了。05江苏The woman biologist stayed in Africa studying wild animals for 13 years before she returned.Oh, dear!Shea lot of difficulties!A.may go throughB.might go throughC.ought to have gone throughD.must have gone through答案D考点考查 “情态动词+have done”。解析从语境分析, 表示某人一定干过某事, 而且是对过去情况肯定的推测, 故应用must have done。C项相当于should have done表示对对方的责备, 意思是 “应该做而未做”, 在此不符合题意。06全国Theres no light ontheybe at home.A.cant B.mustnt C.neednt D.shouldnt答案A考点考查情态动词的用法。解析句意为：（家中）没有亮灯, 他们肯定不在家。此处要用情态动词表推测, 且用于否定句表示 “肯定不”, 故cant符合要求。must表推测时不用于否定句, mustnt表示 “禁止, 不许”；neednt表示 “不需要”；shouldnt表示 “不应当”, 故A项符合要求。06全国Eliza remembers everything exactly as if ityesterday.A.was happeningB.happensC.has happenedD.happened答案D考点考查虚拟语气的用法。解析as if仿佛, 好像, 其后的从句可出现虚拟语气。句意为：Eliza清楚地记得每一件事, 仿佛它是昨天发生的！句中remembers为一般现在时, 故as if从句中用一般过去时来表示虚拟语气。06全国We hope that as many people as possible join us for the picnic tomorrow.A.need B.must C.shouldD.can答案D考点本题考查情态动词的用法。解析句意为：我们希望尽可能多的人能参加我们明天的野餐。用can.表示可能性。06北京 Whats the name? Khulaifi.I spell that for you?A.ShallB.WouldC.CanD.Might答案A考点本题考查情态动词的用法。解析shall在问句中征求对方意见, 主要用于第一人称。答语句意为： “我给你拼写一下好吗？”06天津Wehave proved great adventurers, but we have done the greatest march ever made in the past ten years.A.needntB.may notC.shouldntD.mustnt答案B考点本题考查情态动词的用法。解析句意为：我们或许还没有证明是伟大的探险者, 但我们已取得了在过去的10年里的最伟大的进展。故应用may not。06浙江 Could I have a word with you, mum? Oh dear, if you.A.can B.must C.may D.should答案B考点考查情态动词的用法。解析句意为：妈妈, 我可以和你说句话吗？” “噢, 亲爱的, 如果你非要说的话。”must表示必须要做的事。06福建If it were not for the fact that shesing, I would invite her to the party.A.couldntB.shouldntC.cantD.might not答案C考点考查情态动词的用法。解析题中that引导同位语从句。 “she cant sing”是一个事实, 是指在能力、技能等方面不能、不会。06湖南Some aspects of a pilots jobbe boring, and pilots often work at inconvenient hours.A.can;have toB.may;canC.have to;mayD.ought to;must答案A考点考查情态动词的用法。解析句意为：飞行员工作的某些方面可能是令人厌倦的, 并且飞行员经常在不方便的时候工作。第一空表示的是客观的可能性, 应用can；而第二空说在不方便的时候还要干, 因此表示客观上的必须, 用have to, 意为 “不得不”。06湖北fired, your health care and other benefits will not be immediately cut off.A.Would you beB.Should you beC.Could you beD.Might you be答案B考点本题考查情态动词的用法。解析句意为：如果你被炒了, 你的医疗保险和其他利益并不会立即取消。与将来事实相反的假设, 从句用答案B项。06山东 May I smoke here? If you, choose a seat in the smoking section.A.should B.could C.mayD.must答案D考点本题考查情态动词的用法。解析由本题语境可知, 空白处应表示 “非得”之意, 故须用must。06江西The weather turned out to be fine yesterday. I the trouble to carry my umbrella with me.A.should have takenB.could have takenC.neednt have takenD.mustnt have taken答案C考点本题考查情态动词的用法。解析句意为:昨天天气不错, 我本没有必要不怕费事带把伞。could have done表示 “本能够做而未做”；should have done表示 “本应该做而未做”；mustnt表示 “禁止, 不许”；neednt have done表示 “本不必做而做了”。take the trouble to do sth.表示 “不怕费事或困难尽力做某事”。06江苏 I think Ill give Bob a ring. You.You havent been in touch with him for ages.A.will B.may C.have toD.should答案D考点本题考查情态动词的基本用法。解析will用于第二人称常用来表示命令、指示, 意为 “务必, 必须”；may表示 “可能, 也许”, 常用于请求许可；have to表示 “不得不”；should可用于表示主观看法、建议、劝说, 意为 “应当, 应该”。在此句中, 答话者表示同意对方的想法。答语句意为：你应该（打个电话）, 你好长时间没与他联系了。故D项符合情景要求。06广东 Must he e to sign this paper himself? Yes, he.A.need B.must C.mayD.will答案B考点本题考查情态动词的用法。解析表示要求时, 肯定回答用must, 否定用neednt。06四川Is Jack on duty today?Itbe him.Its his turn tomorrow.A.mustntB.wontC.cantD.neednt答案C考点本题考查情态动词的用法。解析cant表示否定推测, must表示肯定推测。06陕西As you worked late yesterday, youhave e this morning.A.maynt B.cant C.mustntD.neednt答案D考点本题考查情态动词的用法。解析句意为：既然你昨天工作得那么晚, 今早上你就没必要来了。从意思上显示选择项表示 “没必要”。07全国Hows your tour around the North Lake? Is it beautiful?Itbe, but it is now heavily polluted.A.will B.would C.shouldD.must答案C考点考查情态动词的区别。解析will可用来表示 “意愿；客观必然性等”；would可表示 “意愿；过去常常（现在也可能是那样的）”；should表示 “应该, 理应”；must表示 “必然；一定, 准是”。结合语境可知, 此处用should表示虚拟。句意为： “这本来应该是美丽的, 但是现在它被严重污染了。”07北京In crowded places like airports and railway stations, you take care of your luggage.A.can B.may C.mustD.will答案C考点本题考查情态动词的用法。解析句意为：在像飞机场和车站这样拥挤的地方, 你一定要照看好自己的行李。must表示 “必须, 一定”符合句意。07湖南The biggest problem for most plants, whichjust get up and run away when threatened, is that animals like to eat them.A.shant B.cant C.needntD.mustnt答案B考点本题考查情态动词的用法。解析句意为：对于绝大多数受到威胁时不能起来就逃跑的植物来说, 最大的问题是动物喜欢吃它们。Shant表将来;neednt不必, mustnt禁止, 都不正确。07陕西I told your friend how to get to the hotel, but perhaps Ihave driven her there.A.could B.must C.mightD.should答案D考点本题考查情态动词。解析could have done（过去）可能做过；本能够做；must have done（过去）肯定做过；might have done（过去）可能做过；should have done本应该做（而事实上没做）。由句意 “我告诉你朋友该怎么去旅馆, 但或许我应该开车送她去那儿。”可知应选D项。07四川What does the sign over there read? “No personsmoke or carry a lighted cigarette, cigar or pipe in this area.”A.will B.may C.shallD.must答案C考点本题考查情态动词的用法。解析shall用于第二、三人称, 表示命令、允许、警告等, 此处表示警告。07重庆What do you think we can do for our aged parents?Youdo anything except to be with them and be yourself.A.dont have toB.oughtnt toC.mustntD.cant答案A考点本题考查情态动词的用法。解析dont have to不必；oughtnt to不应当；mustnt禁止, 不允许；cant不可能。答语句意为：“除了与父母呆在一起和做你自己以外, 你不必做任何事情。因此A项符合题意。07浙江My cats really fat.Youhave given her so much food.A.wouldntB.couldntC.shouldntD.mustnt答案C考点考查情态动词。解析句意为：我的猫真胖。你本不应该给她那么多食物。shouldnt have done sth本不应该做某事（暗含做了）。07福建My MP4 player isnt in my bag.WhereI have put it?A.can B.must C.shouldD.would答案A考点考查情态动词。解析由句意 “我的MP4不在我包里。我可能把它放哪儿了？”可知应选A。can have done过去可能做过而must have done “过去肯定做过”, 只能用于肯定陈述句；should have done本应该做过（而事实上没做）；would have done只能用于虚拟语气。07江苏She looks very happy.Shehave passed the exam.I guess so.Its not difficult after all.A.should B.could C.mustD.might答案C考点本题考查情态动词的用法。解析must have passed the exam肯定是通过考试了, 由前句中的 “happy”和下句中的 “not difficult after all”可以推知。07山东Theytwo free tickets to Canada, otherwise theyd never have been able to afford to go.A.had got B.got C.have gotD.get答案B考点本题考查情态动词的用法。解析 “otherwise theyd never have been able.”这一句用了与过去事实相反的虚拟语气；而 “他们弄到了两张去加拿大的免费票”却是事实, 故用一般过去时。07上海Guess what？ I have got A for my term paper.Great!Youread widely and put a lot of work into it.A.mustB.shouldC.must haveD.should have答案C考点本题考查情态动词的用法。解析由 “have got A”可知是对过去发生事情的推测, 故用 “情态动词+have done”结构。must have done表示 “必定做过某事”, 符合题意。07安徽The teacherhave thought Johnson was worth it or she wouldnt have wasted time on him, I suppose.A.should B.can C.wouldD.must答案D考点本题考查情态动词的用法。解析must have done表示对过去所做事情的肯定判断, 表示 “一定”。07江西Where is my dictionary? I remember I put it here yesterday.Youit in the wrong place.A.must put B.should have putC.might put D.might have put答案D考点考查情态动词表推测的用法。解析由yesterday可知A、C两项错误；should应该, 理应；might或许, 可能, 显然D项正确。08全国Lizawell not want to go on the tripshe hates traveling.A.willB.canC.mustD.may答案D考点本题考查情态动词的用法。解析句意为：Liza极有可能不想去旅行她讨厌旅行。may well很可能, 极有可能, 表示猜测。当表示猜测时, will和can不能与well连用, must只能用于肯定句中。08北京John promised his doctor henot smoke, and he has never smoked ever since.A.mightB.shouldC.couldD.would答案D考点本题考查情态动词的用法。解析句意为:约翰答应医生他不再吸烟, 从那以后, 他再也没有吸过烟。由句意可知空格处表示允诺, 故应选择D项。08天津Shehave left school, for her bike is still here.A.cantB.wouldntC.shouldntD.neednt答案A考点本题考查情态动词的用法。解析句意为：她不可能离开了学校, 因为她的自行车仍然在这儿。cant表示不可能；wouldnt have done表虚拟；shouldnt have done本不该做(却已做了）；neednt have done本没必要做(但已做了）。08江西What a pity!Considering his ability and experience, hebetter.A.need have done B.must have doneC.can have doneD.might have done答案D考点本题考查情态动词的用法。解析句意为：太遗憾了！鉴于他的能力和经验, 他本可能做得更好。need have done本来有必要做（而没做）；must have done是对过去发生的事情的肯定的推测, 表示 “过去一定做了”；can have done是对过去发生的事情的不肯定的推测；might have done表示 “本来可以”。08湖南You dont have to know the name of the author to find a book.You find the book by the title.A.must B.need C.canD.would答案C考点本题考查情态动词的用法。解析句意为：要找到一本书你不一定非要知道作者的名字。你可以根据书的标题找到这本书。can表示 “可以, 能够”。08陕西What sort of house do you want to have? Something big?Well, itbe bigthats not important.A.mustntB.needntC.cantD.wont答案B考点本题考查情态动词的用法。解析句意为：“你想要什么样的房子？要大的吗？” “噢, 它不需要很大, 那不重要。”由.thats not important.这一语境可知, 空格处应表示 “不需要”, 故须用neednt。08四川Although thissound like a simple task, great care is needed.A.mustB.mayC.shallD.should答案B考点本题考查情态动词的用法。解析句意为：尽管这听起来可能像一项简单的任务, 但是需要非常仔细。must一定, 必须；may可能, 可以；shall将要；should应该。各自表达的意义不同, 选may最妥当。08重庆I cant find my purse anywhere.Youhave lost it while shopping.A.mayB.canC.shouldD.would答案A考点本题考查情态动词的用法。解析may表达推测之意, 意为 “可能”。08浙江Yoube hungry already you had lunch only two hours ago!A.wouldntB.cantC.mustntD.neednt答案B考点本题考查情态动词的用法。解析句意为：你不可能饿了, 你两个小时之前才吃的午饭！cant指不可能；mustnt表猜测时, 不能用于否定句；Neednt指没有必要。08福建It is usually warm in my hometown in March, but it be rather cold sometimes.A.must B.can C.should D.would答案B考点本题考查情态动词的用法。解析must必然, 一定；can可能；should应该；would（过去）将, 总会。本题提供的语境是 “有时可能会”。08辽宁Peterbe really difficult at times even though hes a nice person in general.A.shall B.shouldC.can D.must答案C考点本题考查情态动词的用法。解析句意为：虽然彼得总体上来说是一个好人, 但有时真的难以相处。can在这里不表示主观的推测, 而表示客观的可能性。08江苏Im sorry.Iat you the other day.Forget it.I was a bit out of control myself.A.shouldnt shoutB.shouldnt have shoutedC.mustnt shoutD.mustnt have shouted答案B考点本题考查情态动词的用法。解析句意为：“对不起, 几天前我本不应该朝你大喊大叫的。” “不要放在心上。我自己有点情绪失控。”shouldnt have done sth.本不应该做某事(但已经做了)。08山东Thank you for all your hard work last week.I dont think we it without you.A.can manageB.could have managedC.could manage D.can have managed答案B考点本题考查情态动词的用法。解析could have done本能够做某事（但没做）。09安徽Some people who dont like to talk much are not necessarily shy；they just be quiet people.A. must B. may C. should D. would答案B考点本题考查情态动词的用法。解析有些人不喜欢讲话are not necessarily shy, 他们可能是安静的人, 表示 “可能”之意。09北京One of the few things you _ say about English people with certainty is that they talk a lot about the weather.A. need B. must C. should D. can答案D考点本题考查情态动词的用法。解析关于英语的话题中, 你绝对有把握谈论的极少几个话题之一, 就是很多时候都在谈论天气。09湖南 Its the office! So you know eating is not allowed here. Oh, sorry.A. must B. will C. may D. need答案A考点本题考查情态动词的用法。解析句意为：这是办公室！因此你必须知道吃的不允许带到这里。must表示 “绝不”的意思。09海南What do you mean, there are only ten tickets? There be twelveA. should B. would C. will D. shall答案A考点本题考查情态动词的用法。解析你这是什么意思, 只有十张票吗?应该有十二人。should表示 “应该, 应当”。09上海It_ have been Tom that parked the car here, as he is the only one with a car.A. may B. can C. must D. should答案C考点考查情态动词表推测。解析通过意思我们知道是表示可能的推测, 而且是过去的可能, 表达的是一定是.比较肯定的推测, 所以我们用must have done 的形式。09四川I dont care what people think.Well, you _A. could B. would C. should D. might答案C考点考查情态动词的用法。解析答话的人提了一个建议你应该关注别人对你的评价的。should可以用来向别人提建议, 所以答案为：C09天津This printer is of good quality. If it _ break down within the first year, we would repair it at our expense.A. would B. should C. could D. might答案B考点考查情态动词的用法。解析句意为：这个打印机的质量很好, 如果在一年内出现故障, 我们将免费维修。 09重庆Hi, Tom. AnyideawhereJaneis?She_intheclassroom. Isawhertherejustnow.A. shallbe B. shouldhavebeenC. mustbe D. mighthavebeen答案C考点考查情态动词表推测的用法。解析根据题意, 我刚刚看见她在教室, 可以肯定推测她一定在那儿。09全国III cant leave. She told me that I stay here until she es back.A. can B. must C. will D. may答案B考点考查情态动词的用法。解析根据前文, “我不能走”, 可以判断她告诉我 “必须”呆在这儿。09江苏He did not regret saying what he did but felt that he it differently.A. could express B. would expressC. could have expressed D. must have expressed答案C考点虚拟语气。解析could have expressed it differently.他要是用另一种方式来说该多好呀。09福建But for the help of my English teacher, I the first prize in the English Writing petition.A. would not win B. would not have won C. would win D. would have won答案B考点虚拟语气。解析此处虚拟语气表示与过去事实相反, 句子谓语动词用would/should/could/might + have done结构, 故选B。10安徽Jack described his father, who _a brave boy many years ago, as a strong willed manA. would be B. would have been C. must be D. must have been答案D考点本题考查情态动词推测用法。解析句意为 “杰克把他的父亲描述为一个意志坚强的人, 他的父亲多年前肯定很勇敢。”用must have been表示对过去事情的肯定推测。10安徽Bob would have helped us yesterday, but he-_A. was busy B. is busy C. had been busy. D. will be busy答案A考点本题考查虚拟语气与时态。解析前句表示对过去的虚拟, 而but之后表示过去的客观事实, 故用一般过去时态。10湖南You buy a gift, but you can if you want to.A. must B. mustnt C. have to D. dont have to答案D考点本题考查情态动词。解析dont have to 意为 “没有必要”, 符合语境, 句意为：“你没有必要买礼物, 但如果你想买的话, 你也可以买。”10湖南If he my advice, he wouldnt have lost his job.A. followed B. should follow C. had followed D. would follow答案C考点考查虚拟语气。解析根据 “wouldnt have lost”可判断if引导的状语从句表示与过去事实相反的虚拟, 故选C项。10江西I have told you the truth. _ I keep repeating it?A Must B Can C May D Will答案A考点考查情态动词的用法。解析must 必须, 一定 can 可以, 能够 may 也许 will 意愿, 倾向性动作, 前半句说我告诉你事实了, 这里用的是现在完成时, 表示过去的动作对现在造成了影响, 既然我已经说了, 我还必须重复一遍吗？10山东I_ have watched that movie itll give me horrible dreams. A. shouldnt B. neednt C. couldnt D. mustnt答案A考点本题考查情态动词的用法。解析句意应为 “我本来不应该看那部电影的-它会使我做噩梦的。”表示 “本来不应该做而做了某事”用shouldnt have done, 所以A项正确。10天津Mark have hurried. After driving at top speed, he arrived half an hour early.A. neednt B. wouldnt C. mustnt D. couldnt答案A考点考查情态动词。解析句意：迈克本来不必要那么忙的。这么高速驾驶之后, 他早半个小时到达了。根据后面的语境, 提前半个小时到达, 说明Mark本来不必那么匆忙, 所以用neednt have done 结构, 表示 “本来不必要做某事的而实际上做了”。10天津John went to the hospital alone. If he me about it, I would have gone with him.A. should tell B. tells C. told D. had told 答案D考点考查虚拟语气。解析句意：约翰独自去了医院。如果他告诉我的话, 我会跟他一起去的。前一句是陈述语气, 说明动发生在过去, 而且后一句的主句已经是would have gone说明是与过去事实相反的虚拟语气。与之对应的从句结构, 应该用had +过去分词。10四川 I take the book out? Im afraid not.A. Will B. May C. Must D. Need答案B考点考查情态动词。解析表请求可用情态动词can, may, could, might ,表允许用can, may.句意为： “我可以将这本书带出去吗？” “恐怕不行”。故应选表情请求的情态动词may。正确答案为B。10全国Just be patient .You _ expect the world to change so soon .A. cant B. neednt C. may not D. whether答案A考点考查情态动词。解析句意：耐心一点儿, 你不能期望世界变化如此快。通过选项此题考查情态动词, cant在否定句中可以表示推测, 译为不可能,可以表示能力, 译为不能够, 也可以表示命令, 不允许,