21. —— What do you think made Mary so upset?
—— ____________ her new bicycle.
A. As she lost B. Lost C. Losing D. Because of losing
22. Please keep me of how our business is going when I am away on business .
A.to be informed B.informed C.on informing D.informing
23. . -What do you require of me on earth?
-You ________ focus on your study, especially your English requires ________.
A. are required to; paying more attention B. have to; being improved
C . had better; to be paid attention D. should; being paid attention to
