21. --- I’m not good at singing, you know.
--- . It’s just for fun.
A. All right B. No problem C. Come on D. Cheer up
22. The Internet and the effect brought about did a lot of good to our daily life and work.
A. that B. what C. which D. it
23. ____ no cash for food, he broke into an old woman's house, hoping to steal some money.
A. Because B. As C. Since D. With
24. Not until the train pulled into the next station _____ her suitcase gone.
A. Mary had found B. had Mary found
C. did Mary find D. Mary found
