八码滚雪球技巧图片

简介：After the Jiajing Dynasty, the Mongols declined, and the captives in Liaodong gradually became a serious problem. Therefore, the Ming Dynasty's defense focus shifted eastward from Xuanhua and Datong to the front line of Shanhaiguan. Especially after the Wanli Dynasty, the threat of the captives increased day by day, and the imperial court would attack them every year. The Great Wall along Shanhaiguan was repaired and reinforced.