21. ——Tom, you are caught late again.
    ——Oh, ____.
A. not at all B. just my luck C. never mind D. that's all right

22. ——What do you think of the concert?
    ——I really enjoy it. I didn't expect it was ____ wonderful.
A. as B. more C. most D. very

23. The engineers made two big plans for the dam, ____ was never put in force.
A. one of them B. which C. one of which D. every one of which

24. I have no one ____ me, for I am a new comer here.
A. help B. helping C. to help D. to have helped

25. The little girl couldn't work the problem out. She wasn't ____ clever.
A. that B. much C. enough D. too