Song Bing, a constructor of the rail line, shows the ticket in a bullet train at the Huaibei Railway Station in Huaibei, east China's Anhui Province, Dec. 28, 2017. With a designed speed of 250 km per hour, the 27.1-km Huaibei-Xiaoxianbei high-speed passenger rail line started operation. (Xinhua/Liu Junxi)