问题补充：
----- in the workshop. Please stop it.
----- Sorry. I.
A. Smoking is not allowed, don’t know
B. Not smoking, an not sure
C. Don’t smoke, have no idea
D. Smoking is forbidden, didn’t know
答案：
A. Smoking is not allowed, don’t know
B. Not smoking, an not sure
C. Don’t smoke, have no idea
(答案→)D. Smoking is forbidden, didn’t know
解析：不知道是在对方告诉之前，故需过去时。
