--Who is making much noise?---It be Timmy. He is sleeping now.A. can’t B. may notC. mustn

问题补充：

--Who is making much noise?

---It be Timmy. He is sleeping now.

A. can’t

B. may not

C. mustn’t

D. couldn’t

答案：

(答案→)A. can’t

B. may not

C. mustn’t

D. couldn’t

解析：从下文来看前面应是否定意思，D选项时态不符，所以选a,不能。