1：You ___ all those clothes. We have a washing machine to do that sort of thing. A：needn’t have washed B：shouldn’t have washed C：must not have washed D：can not have washed ...

20：Once environmental damage ___, it takes many years for the system to recover. A：has done B：is to do C：does D：is done ...

14：___ his head high, the manager walked into the room to attend the meeting ___ then. A：Holding...being held B：Held...holding C：Having held...held D： Held… be held ...

2：The operation, if not done in time, ___ become complicated. A：tempts to B：attempts to C：tends to D：attends to ...

21：His honesty and effectiveness ___  him great respect. A：provided B：earned C：obtained D：acquired ...

15：Energy is ___makes things work. A：what B：something C：anything D：that ...

9：He is the most diligent student ___ I have ever known. A：who B：that C：which D：of whom ...

3：___ in bed for several hours, he felt much better. A：Having lain B：Laying C：Having lained D：Lying ...

22：The nurses in that hospital are very good ___ the patients there. A：at B：for C：to D：with ...

16：Before he started work, I asked the builder to give me an___of the cost of repairing the roof. A：assessment B：estimate C：announcement D：evaluation ...