甲组:1,3,5,7,9,11,13,15,17,19乙组:2,4,6,8,10,12,14,16,18,20.每次分别从甲乙两组

问题描述:

甲组:1,3,5,7,9,11,13,15,17,19乙组:2,4,6,8,10,12,14,16,18,20.每次分别从甲乙两组

问题好像不完整