31. Can you tell me the way ____ I can improve my English?

A. in which　 B. which　　 C. by which　 D. at which

30.I______on my essay these days and it won’t be ready until a week later.

A. have been working　 B. worked 　C. have worked　 D. work

29. -----Do you remember the time when we first met?

------- -Yes, you _______at　 Wuhan University.

A.　　 study　 B. had studied　 C. studied D. were studying

28. In our class, when the bell rang and the teacher closed his book, it was a ______ for everyone to stand up.

A. signal　 　B. chance　 C. mark　　 D. measure