24. A. been exploded B. exploded C. been exploding D. exploding
23. A. under B. on C. from D. to
22. A. busy B. always C. occasional D. occasionally
21. A. which B. where C. there D. here
19. The photo was taken ______ stood the famous Bird’s Nest in Beijing during the Olympics.
A. which B. in which C. where D. there
18. Whenever asked to help me with my lessons, he always refuses, ______ he is too busy.
A. to say B. saying C. says D. having said
17. To our surprise, we got ______ people to attend the meeting as we expected.
A. as twice B. twice many C. twice many as D. twice as many
16. I had just stepped out of the bathroom ______ I heard the steps.
A. while B. when C. since D. after
15. ---- ______ he dropped out of school?
----His family had run into financial difficulties.
A. Why was it that B. Why was that
C. Why was that it C. Why was it