六个数字有多少种组合不重复简介：In the central tent, Qin Fen called the four branch leaders over and said solemnly: Everyone, do you know how many students Qinglong College recruits every year?
In the central tent, Qin Fen called the four branch leaders over and said solemnly: Everyone, do you know how many students Qinglong College recruits every year?
