21. — What are you going to do this weekend?
— _____. If time permits, I may go to Shanghai with my friends.
A. Don't mention it B. It doesn't matter C. Forget it D. It depends
22. — Have you figured out how much the trip will cost? —$4,000, or _____ like that.
A. anything B. everything C. something D. nothing
23. The air quality in the city, ______ is shown in the report, has improved over the past two months.
A. that B. it C. as D. what
