21．Everything comes with __ price; there is no such __ thing as free lunch in the world.
A. a;a B the ;/ C. /; the D a ; /
22.The car passed through the street ___ are thought was a very dangerous speed.
A which B at which C. what D at what
23. There’s no bus now, and we can’t get home __ by taxi.
A. other than B. rather than C more than D less than
