21. Have you heard ______ news？The piece of _______ petrol is going up again!
A. the, the B. 不填，the C. the, 不填 D. 不填，不填
22. I thought we’d be late for the concert, ______ we ended up getting there ahead of time.
A. but B. or C. so D. for
23. What a pity. Considering his ability and experience, he ____ better.
A. need have done B. must have done
C. can have done D. might have done
