3d怎么计算下期的跨度

简介：——Chen Yongfu is good at guarding. Although the Miyun soldiers he led have fully implemented the Beijing camp training method and implemented the Beijing camp system for only four months, they have already achieved initial results. In addition, the east entrance is narrower and more difficult to pass than the west entrance. , under the command of Chen Yongfu, the Miyun soldiers also successfully blocked the Mongolian soldiers coming down the mountain for two hours.