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。
21. ---Mum, it’s so dark here, I am afraid.
--- _____________.
A. I’m afraid not B. Never mind C. Take it easy D. How silly you are
22. He was about to tell me the secret _______someone patted him on the shoulder.
A. as B. until C. while D. when
