第一节：单项选择（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 was listening to _______ wonderful music when there was _______ knock at the door.
A. a; / B. the; the C. a; a D. the; a
22. --- How do you like working here?
--- _____. To be honest, I miss my former colleagues.
A. Not so good B. More than satisfactory
C. I like it here D. Very much
