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.I need some fresh air, so I am going out for a walk.— .
A You’d better not B Have fun C With pleasure D I sure am
22.—Excuse me! How can I get to the nearest post office?
—Walk along this road for a few minutes, ________ you’ll make it.
A. so B. and C. but D. or
