—How about singing songs with me?—I’m sorry I can’t. I help my father with his work. A. ha

问题补充：

—How about singing songs with me?

—I’m sorry I can’t. I help my father with his work.

A. have to B. can C. may

答案：

解析：have to必须，不得不；can 能，可能；may可以。句意：和我一起唱首歌怎么样？——抱歉，我不能。我必须帮助我的父亲做他的工作。结合语境可知选A。