四个数字有多少种组合方式

简介：After chatting for a while, Lin Anqin patted his head and said to himself: I almost forgot, you guys eat first, Su Can, later you take your sister to buy some clothes to change into. Look at your sister shivering from the cold, it’s already late autumn. Wearing summer clothes is really troublesome. Even now that you are grown up, you are still as ignorant as you were when you were a child.