—Please don't tell anybody.—I . I promise.A. can'tB. don'tC. won'tD. mustn't

问题补充：

—Please don tell anybody.

—I . I promise.

A. can

B. don

C. won

D. mustn

答案：

A. can

B. don

(答案→)C. won

D. mustn

解析：C 考察情态动词。Will表示意愿，决心。故C正确。