35. -----May I ask a question after class, Sir?

　 -----_______,　 but not during my lunch break.

A. I’m sorry　　　　　 B. Anytime　　　　　 C. Certainly　　　　 D. Go ahead

34. At the meeting they discussed three different ___ to the study of mathematics.,

A. Approaches　　　　 B. Means　　　　　　 C. Methods　　　　 D. ways

33. ______ this experiment is known to us.

A. Which to do 　 B. Whom to do　 　 　C. How to do　 　D. What to do

32. _______, we watched half a year’s food destroyed before our eyes.

A. Helplessly and sad　　　 　　　　　　　 　B. Helplessly and sadly

C. Helpless and sadly　　　 　　　　　　　 　D. Helpless and sad

31. You are welcome to drop in at my new house whenever______.

A. it is convenient to you　　　　　　　　 　B. it is convenient of you

C. you are convenient　　 　　　　　　　 　D. you convenient