大小单双玩法概率学简介：The Zhangcheng in this poem refers to Zhangjiakou. The poet calls Zhangjiakou the first critical point of the Great Wall. Although it is a bit exaggerated, it is not completely unfounded.
The Zhangcheng in this poem refers to Zhangjiakou. The poet calls Zhangjiakou the first critical point of the Great Wall. Although it is a bit exaggerated, it is not completely unfounded.
