21. — Do you think advertisement is _______ help when you look for a job.
    — Well, it depends. Anyway, it gives me more of_______ chance to try.
    A. a; a           B. a; the          C. the; the         D. /; /
22. You ought to have thought of that, but you _______.
A. haven’t        B. didn’t         C. don’t           D. can’t
23. The place _______ the bridge is supposed to be built should be _______ the cross river traffic is the heaviest.
A. which; where   B. at which; which C. at which; where D. which; in which