24. The bell______ the end of the period rang and we had to stop our discussion.

A. indicating　 B. indicated　 C. to be indicated　 D. being indicated

23. I think he is very ______ to finish the work ahead of time.

　 A. possible　　 B. likely　　 C. perhaps　　 D. probable

22._____ we were worried about was _______ they could manage to control the pollution.

A. That; how　 B. That;　 whether　　 C. What;　 that　 D. What; whether

21. - ---What’s the matter with Kim?

　 ---The tickets to the concert she ____ for had been sold out when we got there.

A. wished　　 B. desired　 C. expected　　 D. liked