17．       The        he said it he knew what a mistake he had made.

A．moment                 B．time                       C．occasion                D．hour

18．       I        rather solve the problems in my farm myself than seek the help of other people.

A．should                   B．shall                      C．would                    D．will

19．       From what has been discussed above, we may safely draw the        that its disadvantages are far greater than its advantages.

A．solution                  B．conclusion              C．answer                  D．attention

20．       By the time you have completed the essential training, you        exposed to virtually every new feature of the course.

A．will have been         B．will be                   C．would have been     D．would be

21．       Too often teachers’        with parents involve complaints about children’s misbehaviors and laziness.

A．acquaintances         B．association             C．conferences            D．consultations

22．              I admit that the problems are difficult, I don’t agree that they cannot be solved.

A．When                    B．Where                   C．While                    D．Why

23．       He should        be allowed to get up until he has completely recovered  from his illness.