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. ---Could I ask you a rather personal question, Sir?
---Sure, ______.
A. you could B. my pleasure C. good idea D. go ahead
22. ---Hello! Golden Bay Resort. Can I help you?
---Do you have a room ______ for this weekend?
A. available B. useful C. possible D. empty
23. It’s obvious that EXPO shanghai 2010 _______ a great success.
A. kept B. showed C. proved D. remained
