Aerial photo taken on Dec. 21, 2020 shows a CR300AF bullet train operating in a train maintenance station in Guiyang City, southwest China's Guizhou Province. A new-type Fuxing bullet train CR300AF, with a designed speed of 250 km per hour, set off from Guiyang to Liupanshui on Monday, which marked the debut of this type in the southwest China. (Photo by Yang Jiewen/Xinhua)