It's no secret to us, but he alone is in the dark. It means .
A. nobody but him knows the secret
B. we all know the secret except him
C. it's so dark that he can't see everything clearly
D. only the needs to keep the secret
网友回答
A. nobody but him knows the secret
(答案→)B. we all know the secret except him
C. it's so dark that he can't see everything clearly
D. only the needs to keep the secret
解析： in the dark表示“蒙在鼓里，一无所知”。