- Another cup of coffee? ---No. thanks. I be off. Marry is waiting for me.A. canB. may

问题补充：

--- Another cup of coffee?

---No. thanks. I be off. Marry is waiting for me.

A. can

B. may

C. must

D. might

答案：

A. can

B. may

(答案→)C. must

D. might

解析：根据后文内容Marry is waiting for me.可知选择情态动词must，故选C符合题意。