九个数字选四个有多少组合

简介：Huang Zongxi was fine and had a calm expression, but Hou Fangyu was nervous and dry. When he arrived at the door of the crown prince's study in the back hall, the chamberlain announced that the crisp sound of "announcement" came from inside. Hou Fangyu could hardly move, and Huang Zongxi pulled him. It took him to regain his composure.