（整理版高中英语）高二英语语法·剖析·活用（Unit21　HUMANBIOLOGY）北师大

1、高二英语 语法·剖析·活用unit 21human biology 北师大版选修7虚拟语气条件从句主句与现在事实相反if+主语+动词过去式(be的过去式一律用were)主语+would+动词原形与过去事实相反if+主语+had动词过去分词主语+ would+have+动词过去分词与将来事实相反were+不定式should +动词原形主语+would (should)+动词原形虚拟语气混合条件句在虚拟语气中，主句与从句的动作发生在不同的时间，这时主、从句谓语动词的形式因时间的不同而不同，这叫做混合条件句，也叫做错综时间条件句。这样的句子不仅仅是时间的不同，更重要的是事实和假设

2、的混合。这种虚拟情况的动词形式应根据实际情况灵活使用。如：if you had asked him yesterday, you would know what to do now.如果你昨天问他，你现在会知道做什么。if you hadnt watched tv that late last night, you wouldnt be so sleepy.如果你昨天晚上看电视不那么晚，你现在不会这么困倦。you would be much better now if you had taken my advice.假设你接受了我的意见，你现在就会好多了。had mr. li received

3、 two more votes in the last election, he would be our chairman now.如果李先生在最后的竞选中，多得两票，他现在会成为我们的主席。虚拟条件句的倒装虚拟条件句的从句局部如果含有were, should或had, 可将if省略，再把were, should或had移到从句句首，实行倒装。if it had rained last night , it would be very cold today.had it rained last night, it would be very cold today.如果昨天下雨了，今天会很冷的

4、。if you had come earlier, you could see him now.=had you come earlier, you could see him now.如果你早来一点的话，你现在能够见到他。if it had rained, the crops would be green now.=had it rained, the crops would be green now.如果下过雨的话，庄稼现在会绿绿的。活学活用25. dont you think it necessary that he _ to miami but to new york?i agree,

5、 but the problem is _ he has refused to.a. will not be sent; thatb. not be sent; thatc. should not be sent; whatd. should not send; what答案:c解析：it作形式宾语，that引导的从句作真正的宾语，necessary作宾语补足语时，从句的谓语要用“should+动词原形或动词原形。what引导表语从句，作has refused to的宾语。26. if i _ plan to do anything i wanted to, id like to go to

6、tibet and travel through as much of it as possible.a. wouldb. couldc. had tod. ought to答案:b解析：根据句意可判断出是虚拟语气，要用could。27. look at the trouble i am in! if only i _ your advice.a. followedb. would followc. had followedd. should follow答案:c解析：if only意为“但愿，要是就好了，主要用于虚拟语气中，用以表达愿望或非真实条件。表示现在用一般过去时，表示过去用过去完成时

7、，表示将来用过去将来时。28. it is hard for me to imagine what i would be doing today if i _ in love, at the age of seven, with the melinda cox library in my hometown.a. wouldnt have fallenb. had not fallenc. should falld. were to fall答案:b解析： 根据句意和i would be doing可以判断这是虚拟语气。at the age of seven是表示过去的时间状语，if从句中的谓语

8、要用had not fallen，表示对过去情况的假设。29. _ be sent to work there?a. who do you suggestb. who do you suggest that shouldc. do you suggest who shouldd. do you suggest whom should答案:a解析：suggest后接宾语从句时，从句的谓语动词要用should do/be done或do/be done。30. how i wish every family _ a large house with a beautiful garden!a. ha

9、sb. hadc. will haved. had had答案:b解析：wish后接宾语从句时，从句中的谓语动词要用虚拟语气，表示动作发生在现在时，宾语从句的谓语要用一般过去时。31. he hesitated for a moment before kicking the ball, otherwise he _ a goal.a. had scoredb. scoredc. would scored. would have scored答案:d解析：otherwise常与虚拟语气连用，表示过去发生的事要用would have scored。句意为：在踢球前他犹豫了一会儿，否那么他就会射中球门。32. what would have happened, _ as far as the river bank?a. bob had walked fartherb. if bob should walk far