3. would rather(宁愿),would sooner(宁愿), had rather(宁愿) 等词或短语后面的从句中的谓语动词应使用一般过去时表示虚拟语气，表示与过去相反的也可用过去完成时

　　4) I’d rather you anything about it for the time being.

　　［A］ do

　　［B］ didn’t do

　　［C］ don’t

　　［D］ didn’t

　　5) I rather you did it.

　　［A］ had

　　［B］ should

　　［C］ shall

　　［D］ have

　　6) I much rather it was forgotten.

　　［A］ will

　　［B］ could

　　［C］ would

　　［D］ shall

　　2. 当wish的宾语从句表示一种愿望、要求时，可用过去时，也可用would＋动词原形

　　I wish you would stay here longer. (我希望你在这儿多呆一会。) / She wishes you wouldn't go. (她希望你不要走。)

　　1. 动词wish后跟由that引导的宾语从句(that经常被省略)要用虚拟语气表示一种不可实现的愿望。宾语从句中用过去时(be 用were的形式)表示与现在事实相反,用过去完成时表示与过去相反

　　She wishes she had more money. (她真希望有更多的钱。) / I wish I didn't say that. (要是我不说这件事就好了。) / I wished I were not so worried. Then I would not have had the accident. ( 我要是不那么忧郁就好了，那也就不会发生那场事故了。)

　　1) I wish I knew ［A］ you were arriving ［B］ today. I would have met ［C］ you at ［D］ the station if I had.

　　2) She wishes that we didn’t send ［A］ her the candy ［B］ yesterday because ［C］ she’s on ［D］ a diet.

　　3) My brother is in ［A］ California on ［B］ vacation，but I wish he was ［C］ here so that he could help me repair my car ［D］ .

　　4. 与将来的事实可能相反

　　(1) If it should rain tomorrow, I would stay at home. 要是万一 明天下雨，我就呆在家里不出去。 事实上 现在天气很好，明天下雨的可能性应该不大，不过也说不准。

　　(2) If I should see her next Monday, I would tell her about it. 如果下周一我能见到她的话我就把这件事告诉她。

　　1) D为正确答案。

　　2) D为正确答案。

　　3) C为正确答案。

　　4) B错。改为would have not。

　　5) A错。改为would have been。

　　6) B为正确答案。

　　7) D为正确答案。

　　II 虚拟语气的特殊表现形式

　　1) Violetta has a curious ［A］ expression on ［B］ her face as though she was smiling ［C］ about something that amused her ［D］ .

　　We dare not play jokes on Mr. Wang lest he should become angry. (我们不敢跟王先生开玩笑，恐怕他生气。)

　　He hurried on, lest he should drop out in the forced match. (他加紧步伐，生怕在急行军中掉队。)

　　Every attention must be paid to him lest he (should) feel that he is inferior to my other guests. (我对他特别关照，唯恐他感觉到比我的其他客人低人一等。)

　　He’s working hard for fear that he should fail in the exam. (他加紧学习唯恐考试不及格。)

　　He worked very hard; otherwise he might have failed. (他刻苦工作，不然他就失败了。)

　　We could have done better under more favorable conditions.(假设我们有更有利条件，我们还会做得更好。)

　　2) But for his help，I .

　　［A］ should not have succeeded

　　［B］ had not succeeded

　　［C］ did not succeed

　　［D］ have not succeeded

　　3) The complex society of a modern ［A］ civilization would be ［B］ impossible not having ［C］ the art of writing ［D］ .

　　4) But that he came to help me, I .

　　［A］ could not have succeeded

　　［B］ did not succeed

　　［C］ could not succeed

　　［D］ can’t but succeed

　　If I had a bike(now), I would have lent it to you yesterday. 假如我有自行车，昨天早就借给你了。(主句与过去事实相反，从句与现在事实相反。) I am very sorry if I had done anything wrong to you, but I am sure that it was unintentional.(如果我当时对你作错了什么事，我向你表示抱歉。但我敢保证我不是故意的。)

　　5) If the United States had built more homes for poor people in 1955，the housing problems now in some parts of this country so serious.

　　［A］ wouldn’t be

　　［B］ will not have been

　　［C］ wouldn’t have been

　　［D］ would have not been

　　6) If you had not studied the problem carefully until recently .

　　［A］ you will find any difficulty now

　　［B］ you would have found any difficulty now

　　［C］ you would find any difficulty now

　　［D］ you have find any difficulty now

　　五、省略虚拟条件句：虚拟条件从句中的谓语动词如果是were或should(could, might), had等词时，可以省略连词If, 但要将were或should(could, might), had助动词移至主语前形成句子例装(参见第十三章“倒装句”)

　　7) today, he would get there by Thursday.

　　［A］ He is starting out

　　［B］ If he starts out

　　［C］ Would he start out

　　［D］ Were he to start out.

　　8) ，John would not have failed.

　　［A］ If he has listened to me

　　［B］ Had he listened to me

　　［C］ If he listened to me

　　［D］ As soon as he listened to me

　　9) I known it，I should have told him.

　　［A］ Have

　　［B］ Had

　　［C］ Having

　　［D］ If

　　10) Hadn’t my car broken down，I the train.

　　［A］ should have caught

　　［B］ might catch

　　［C］ could catch

　　［D］ had caught

　　六、例题解析

　　1) C错。 改为were smiling。

　　2) A为正确答案。

　　3) C错。 改为without。

　　4) A为正确答案。

　　5) A为正确答案。

　　6) C为正确答案。

　　7) D为正确答案。

　　8) B为正确答案。

　　9) B为正确答案。此句为had放句首的一种倒装，相当于If I had……

　　10) A为正确答案。

　　III 从句中须用虚拟语气的情况

　　3. 与将来的事实相反

5) The report would be

［A］ released last January if new developments had not

［B］ made it necessary to revise all conclusions drawn from

［C］ the first series of

［D］ experiments.

　　6) It is said Tom will go to an appointment tommorrow. If he were to come tomorrow, I ask him to go to your place.

　　［A］ will

　　［B］ would

　　［C］ shall

　　［D］ might

　　7) If you to see Mary，what would you tell her?

　　［A］ are

　　［B］ will be going

　　［C］ must

　　［D］ were

　　2. 与过去的事实相反(有时主句中的should have done表示责备或后悔)

　　2) he would have come to class.

　　［A］ If Mike is able to finish his homework

　　［B］ Would Mike be able to finish his homework

　　［C］ If Mike could finish his homework

　　［D］ If Mike had been able to finish his homework

　　3) If the United States had not entered the Second World War，probably the 1940 unemployment rate of 14％ still further.

　　［A］ would rise

　　［B］ would risen

　　［C］ would have risen

　　［D］ had risen

　　4) Top?grade ［A］ diamonds had not ［B］ increased so sharply ［C］ in value in the late seventies ［D］ if one company had not

controlled almost all of the world’s supply.

　　1. 与现在的事实相反

　　1) What type of automobile would you buy ？

　　［A］ if you have free choice to choose the cars available today

　　［B］ if you are free to choose among all the cars available today

　　［C］ if all cars available were free to be chosen by you

　　［D］ if you were free to choose among all the cars available today

（3）在(2)的条件下，若点S是线段EP上一点，过点S作FG⊥EP ，FG分别与边AE、BE相交于点F、G(F与A、E不重合，G与E、B不重合)，请判断是否成立．若成立，请给出证明；若不成立，请说明理由．

（2）如图，以AB为直径作圆，与抛物线交于点D，与抛物线对称轴交于点E，依次连接A、D、B、E，点P为线段AB上一个动点(P与A、B两点不重合)，过点P作PM⊥AE于M，PN⊥DB于N，请判断是否为定值? 若是，请求出此定值；若不是，请说明理由．

已知：抛物线(a≠0)，顶点C (1，)，与x轴交于A、B两点，．

（1）求这条抛物线的解析式．