21. Seeing all the angry faces, she felt a desire to______ .
A. run away B. hold on C. call off D. turn down
【解析】选A。句意：看到一张张愤怒的脸庞，她有想逃跑的欲望。run away 逃跑，逃避；hold on 坚持；别挂断；call off取消；turn down把 (收音机等）开小；把 (声音）调低；拒绝等。
Having walked in the desert for several days, we felt exhausted, but we had to find a pool before the water we had in the bottle______ .
A. ran out of B. ran away C. ran out D. ran off
