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)
从每题所给的A、B、C、D四个选项中,选出可以填入空白处的最佳选项,并在答题卡上将该项涂黑。
21.They desired that they_______ the right to vote.
A. had         B. have    C. are       D. were
22.__________ to sunlight for too much time will do harm to one's skin.
    A. Exposed                                         B. Having exposed 
C. Being exposed                              D. After being exposed