21. _____, we were taken to see the library.
A. We had been shown the classroom
B. Being shown the classroom
C. Having been shown the classroom
D. Having shown the classroom
22. —I wonder if I could possibly use your car for tonight.
—_____. I’m not using it anyhow.
A. Sure, go ahead B. I don’t know
C. Yes, indeed D. I don’t care