九码滚雪球公式

简介：The entire Ningyuan City is slightly square in shape and is three feet high. There are semicircular urns built outside the four gates. The base of the city wall is built with blue strips of stone, with large green bricks on the outside, giant stones on the inside, and rammed loess in the middle. There are two-story pavilions and corridor-style archery towers on the city, and there are sloped climbing paths respectively. There are also forts built on all sides, with Hongyi cannons mounted on them.