biosynthesis of RNA RNA的生物合成.ppt
10虚拟语气,一、非真实条件句中的虚拟语气二、宾语从句中的虚拟语气三、主语从句中的虚拟语气四、表语从句、同位语从句中的虚拟语气五、状语从句中的虚拟语气六、几种特殊的虚拟语气,虚拟语气的主要内容,考题点击:I am not free today.If I _free today,I _ and visit some of my friends.A.am will go B.were,would go C.shall be D.be,must go2.If my lawyer _ here last Saturday,he _ me from going.A.had been,would have prevented B.had been,would prevent C.were,would prevent D.were,would have prevented3.If I were to see Tom,what _ you _ me to tell him?A.are,going to ask B.do,ask C.would,ask D.did,ask,B,A,C,时态,从 句,主 句,表示现在,过去时(be-were),should+动词原形would+动词原形could+动词原形might+动词原形,1.和现在的事实相反,一、非真实条件句中的虚拟语气,时态,从 句,主 句,表示过去,had+过去分词,should+have+过去分词would+have+过去分词could+have+过去分词might+have+过去分词,2.和过去的事实相反,时态,从 句,主 句,表示将来,should+动词原形would+动词原形could+动词原形might+动词原形,3.和将来的事实相反,1)were to+动词原形2)should+动词原形3)动词过去式,考题点击:,1.I went to bed early last night,but I wish I so.A.didnt do B.hadnt done C.havent done D.couldnt do 2.How I wish every family _a large house with a beautiful garden.A.has B.had C.will had D.had had 3.The teacher ordered that students_.A.mustnt smoke B.not smoke C.smoked D.had smoked4.The teacher demanded that the work _ before 4 oclock.A.finished B.finish C.should finish D.be finished,B,B,B,D,二、宾语从句中的虚拟语气,1.wish后面宾语从句中的虚拟语气,表示与事实相反的愿望。其表达形式一般是将从句的谓语动词退后一个时态。例如:1)与现在事实相反:wish+(that)+did(were)I wish I were as healthy as you.I wish that I had a plane.2)与过去事实相反:wish+(that)+had doneI wish I had been to the concert last night.I wish you had written to him.3)与将来事实相反:wish+would/could/might+doI wish he would forgive me.,2.在某些动词后的宾语从句中需用should+动词原形的虚拟语气形式。“should”可以省略。常见的动词有:一个坚持insist;两个命令order,command;三条建议suggest,advise,propose;四项要求demand,request,require,ask;另外有:prefer注意:suggest表 暗示表明 时 insist表坚持认为时不用虚拟语气,He ordered that the students(should)wash the clothes every week by themselves.The doctor suggested that she(should)have an operation at once.,考题点击:Is it necessary that he _ the examination?A.takes B.has to take C.must takeD.take2.It is strange that he _ you this.A.would tell B.should tell C.had told D.has told3.It was ordered that no smoking _ in the library.A.should allow B.be allowed C.will be allowed D.is allowed,D,B,B,三、主语从句中的虚拟语气,基本句型:1.It be+过去分词+that+(should)+动词原形+,过去分词:suggested,requested,ordered,proposed,It is required that nobody(should)smoke here.Its suggested that everybody(should)buy a dictionary.,2.It be+形容词+that+(should)+动词原形+形容词:important,necessary,natural,right,wrong,better,proper,funny,strange,surprising,It is necessary that we(should)have a walk now.Its important that we(should)take good care of the patient.,3.It be+名词(a pity/a shame/no wonder)that+(should)+动词原形+,考题点击:His suggestion that you _ once more sounds reasonable.A.try B.tries C.must try D.can try2.He gave an advice that they _ each other.A.helped B.must help C.help D.had helped3.My suggestion is that a few more people _ there to help me.A.be sent B.have sent C.sent D.should sent,A,C,A,四、表语从句、同位语从句中的虚拟语气,在 suggestion,proposal,idea,plan,order,advice,decision等名词后面的表语从句、同位语从句中要用虚拟语气,即(should)+动词原形。,My suggestion is that we(should)leave at once.,1)表语从句:,2)同位语从句:,I make a proposal that we(should)hold a meeting next week.,考题点击:1.We felt as if we _ each other for years.A.knew B.were knowingC.had known D.have knowing2.He took away the oxygen tank for fear that it _.A.may explore B.exploded C.explode D.had explode,C,C,五、状语从句中的虚拟语气,1、用在由as if,as though引导的状语从句中,表示和现在事实相反或对现在的怀疑,用过去时;表示过去想象中的动作或情况,用过去完成时;表示将来用would+动词原形。It seems as if the man were his brother.This device operated as though it had been repaired.2.用在lest,for fear that和in case引导的状语从句中,这时谓语动词用should+动词原形或动词原形。She closed the windows lest she catch cold.,六、几种特殊的虚拟语气,虚拟倒装句 1.Were it(=If it were)not for their help,we couldnt have got over the difficulties.2.Had I(=If I had)known about it,I would have told you.3.Should anyone(=If anyone should)call,please take a message.What would have happened,_ as far as the river bank?(01 上海)Bob had walked fartherB.if Bob should walk fartherC.had Bob walked fartherD.if Bob walked farther,C,考题点击:,2)错综条件句If you _ him yesterday,you _ what to do now.asked would knowB.had asked would have knownC.asked him knowD.had asked would know,D,If you hadnt bought the ticket last week,how would you go now?,考题点击:,3)介词短语表条件 But for your help,we couldnt have succeeded.Nothing could live without the sun.,考题点击:Without your help,we _ such rapid progress.A.couldnt make B.wouldnt makeC.will not have made D.wouldnt have made,D,4)情境中提供虚拟语气 Suppose there were no gravity,objects would not fall to the ground when dropped.She wasnt feeling very well.Otherwise she wouldnt have left the meeting so early.考题点击:I went by plane;otherwise I _ much longer time.A.could take B.would take C.will have taken D.would have taken,D,5)比较if only与only if only if 表示“只有”;I wake up only if the alarm clock rings.if only 则表示“如果就好了”。其从句中的谓语动词用过去时或过去完成时。If only I knew more.If only the alarm clock had rung.If only 也可用于陈述语气。If only he comes early.If only grandmother _ this together with us now.A.will see B.could see C.must see D.should see,B,考题点击:,6)Its(high/low)time 从句:It is(high)time that 后面的从句谓语动词要用过去式或用should加动词原形,但should不可省略。It is time that the children went to bed.It is high time that the children should go to bed.类似的结构为 would rather 从句:I would rather you attended the meeting this afternoon.,考题点击:It is time that you _ the whole book.A.must go over B.can go overC.went over D.have gone over,C,7)其它手段He telephoned to inform me of your birthday,or I would have known nothing about it.(连词)I might have given you more help,but I was too busy.(连词)Given more time,we could have done it better.(分词短语)Such mistakes could have been avoided.(通过上下文),高考链接:1.I didnt see your sister at the meeting.If she,she would have met my brother.A.has come B.did come C.came D.had come(MET94)2.When a pencil is partly in a glass of water,it looks as if it.A.breaks B.has broken C.were broken D.had been broken(MET95)3.You didnt let me drive.If we in turn,you so tired.A.drove;didnt get B.drove;wouldnt getC.were driving;wouldnt get D.had driven;wouldnt have got(MET95)4.Without the air to hold some of the suns heat,the earth at night,too cold for us to live.A.would be freezing cold B.will be freezing coldlyC.would be frozen cold D.can freeze coldly(上海97),D,C,D,A,5._ it rain tomorrow,we would have to put off the meeting.A.Were B.Should C.Would D.Will(上海94)6.Janes pale face suggested that she ill,and her parents suggested that she a medical examination.A.be;should have B.was;have C.should be;had D.was;has(上海94)7.for the free tickets,I wouldnt have gone to the films so often.A.If it is not B.Were it notC.Had it not been D.If they were not(上海95)8.Yesterday Jane walked away from the discussion.Otherwise,she something.A.had said B.said C.might say D.might have said(上海96),B,B,C,D,goodbye,