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. ---- Where are we going for the vacation, the mountains or the sea?
---- _____.
A. It doesn’t matter B. It’s up to you
C. Don’t mention it D. That’s all right
22. She got _____ great surprise when she opened _____ letter from Finn.
A. a; the B. a; a C. the; a D. the; the
