胆囊定位简介：The trinity of Xijingmen, Laiyuan Fort, and Zhangjiakou Fort formed a complete defense system at the Zhangjiakou border. From a purely military perspective, it was by no means easy for the enemy to break through Zhangjiakou head-on.
The trinity of Xijingmen, Laiyuan Fort, and Zhangjiakou Fort formed a complete defense system at the Zhangjiakou border. From a purely military perspective, it was by no means easy for the enemy to break through Zhangjiakou head-on.
