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. ---It’ll take me at least 2 hours to do this!
---Oh, ______! I could do it in 30 minutes.
A. come on B. pardon me C. you are right D. don’t mention it
22. A club is a place to make frequent ______ with friends.
A. contrast B. contact C. contract D. content
