1 . ____ then what I know now, I would have made different decisions.

A．Should I know

B．I knew

C．I did know

D．Had I known

2 . What a pity! The parents could have survived the earthquake, __________ to save their child.

A．had they not come back	B．have they come back
C．did they not come back	D．did they come back

3 . 按要求完成句子。
1. It is John who ________ _________ __________ ___________ （因…应受责备）the failure.
2. The news________ ______ ______   her hometown.（使她想起了她的家乡）
3. We would have won if we had trained harder.（句型转换）
___________ we __________ harder, we would have ___________.
4. Because they had been warned by their parents, they didn’t dare to go out at night.（句型转换）
________ ________ ________ by their parents, they didn’t dare to go out at night.
5. The pressure from his parents makes him keep progressing.（对划线句进行强调）
_________________________________________________________________
6. The student is allowed to go to the office only if the teacher has given permission.（改成only 引导的倒装句）
____________________________________________________
7. The novel that is written by Mark Twin is very interesting. （改为分词作定语）
____________________________________________________

4 . 完成句子
1. ________ (as, strange, may, sound, it), I was very pleased it was over.
2. Short ________(it, is，as), China’s first ＂space class＂ conveys so much knowledge and is certainly of great importance.
3. ________had she begun ________ she heard someone running up the stairs.
4. ________(I, spend) more time on my studies instead of being addicted to computer games, I would be working in a chain company of Microsoft.
5. —Under no circumstances ________(you, leave) the door to the Data Centre unlocked.
—I promise I’ll be more careful in future.
6. Only when the last tree has died and the last river has been poisoned ________(we，realize) we cannot eat money.

5 . It might have saved me some trouble      the schedule but unforgettably no one told me about it.

A．did I know

B．have I known

C．do I know

D．had I known

6 . 根据句意，用适当的情态动词、虚拟语气填空
1. It is raining heavily outside. You ____________ as well stay here for the night.
2. But for the timely help of the PLA man that day, you ____________(kill) in the car crash.
3. I’m very busy with my Mid-term examination, or I __________ (go) to see the movie with you.
4. While taking exams, a student _________ never be too careful to get high grades.
5. — Tom has arrived. _________ he come in to see you?     —Yes, of course. Call him in.
6. Why are you here? It’s class time and you __________ be in the classroom now.
7. Had you studied harder at college, you __________(get) a better job now.
8. You _________(not) sit in this part. It’s for women and children only.
9. — Let’s go to see a film.   — Why today. I’d rather we __________ (see) a film tomorrow.
10. The old man treated the boy as if he _________ his own son.

7 . Many coral reefs in warm water areas would not be dying out ______ for the pollution accumulated over the previous years.

A．if it is not

B．were it not

C．had it not been

D．if they were not

8 . _____ the free tickets, I would not have gone to the films so often.

A．If it is not

B．Were it not for

C．Had it not been for

D．If it had not been

9 . ---It's a complete pity that you missed the wonderful lecture.
---Terribly sorry! _____my former colleague not come to me unexpectedly.

A．Should

B．Would

C．Had

D．Did

10 . He would have been willing to accompany me________him how important it was to me.

A．if I have told

B．had I told

C．should I tell

D．if I could tell