23．- Why weren't you at the meeting?

　- I ________ for a long distance call from my sister in America.

　A. was waited　 B. was waiting　 C. has waited　　 D. have been waiting

22．While building a tunnel through the mountain, ________ .

A. an underground lake was discovered

B. there was an underground lake discovered

C. a lake was discovered underground　

D. the workers discovered an underground lake

第一节：单项填空(共15小题；每小题1分，满分15分)

从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. The International Red Cross is_______ non-profit organization that cares for the wounded, sick and homeless in wartime, and victims of _______ natural disasters.

A. the; the　　 B. a; the　　 C. the; 不填　　 D. a; 不填

略