—Can you keep a secret?
—You worry—I'm not going to mention it to anyone.
A. needn't
B. couldn't
C. mustn't
D. won't
网友回答
(答案→)A. needn't
B. couldn't
C. mustn't
D. won't
解析：答案：A 考查情态动词。句意为：你能帮我保守秘密吗？你不必担心，我不会向任何人提及的。needn't不必要；couldn't不能够；mustn't禁止；won't将不会。根据句意可知，答案A符合语境。