21.The accident occurred due to _____sudden fog on _____express way.
A.不填;the B. a;不填 C. a; the D.不填;an
22. 一I didn’t tell anybody.
~ _____! Everybody in our class is talking about it.
A. Come on B. Not really C. Forget it D. No way
23.1 don’t want to _____exactly how the system works.
A. give away B. give up C. give back D. give off
24. —I need someone to help me.
一You may select _____you think is suitable.
A. who B. whom C. whomever D. whoever
25 . _____it comes to diet and exercise, we know what to do, but we don’t do what we know.
A. When B.As C. If D. Unless
