第二部分： 英语知识运用(共两节，满分45分)
第一节 单项填空(共15小题；每小题1分，满分15分)
21. I knew _____ John Lennon, but not _____ famous one.
A. 不填; a B. a; the C. 不填; the D. the; a
22. It was some time _____ we realized the truth.
A. when B. until C. since D. before
23. With more forests being destroyed, huge quantities of good earth _____ each year.
A. is washing away B. is being washed away
C. are washing away D. are being washed away
