题目

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 答案：B 解析:  in the dark表示“蒙在鼓里，一无所知”。已知样本数据1，2，4，3，5，则这组数据的中位数是（ ）A．3.5B．3C．4D．2