— you play the piano for us?—Sorry I cant play the piano but I can sing for you.A. CanB

问题补充：

— you play the piano for us?

—Sorry, I can play the piano, but I can sing for you.

A. Can

B. Must

C. May

D. Should

答案：

(答案→)A. Can

B. Must

C. May

D. Should

解析：Can能，能够；Must必须，一定；May 可能；Should应该。根据下文，抱歉，我不能弹钢琴，但是我可以为你唱首歌。Can多表示客观能力，may多用于表示推测，结合语境可知选A。