二、单项选择（每小题1分，共15分）
21. There _____ 60 minutes in _____ hour.
A. are; an B. are; a C. is; the D. is; an
22. Everyone _____ here now .Let’s ______.
A. are ; begin B. are ; to begin C. is ; to start D. is ; start
23. -- Does your father _______home after work?--- Yes, he does.
A. take B.walk to C. Take to D.walk
24. Bob, _____in class.
A. Writes it down B. Write down it
C. Write it down D. Writes down it
