题目

They were surprised that a child should work out the problem they themselves couldn't. 答案：【1】while反复抛掷一个骰子,依次记录下每一次抛掷落地时向上的点数,当记有三个不同点数时即停止抛掷,若抛掷五次恰好停止,则记有这五次点数的所有不同记录结果的种数有A.360种              B.840种             C.600种              D.1 680种