A bullet train passes Yachi River Bridge during a test run on the Chengdu-Guiyang railway in Southwest China's Guizhou province, Dec 2, 2019. The 650-kilometer Chengdu-Guiyang railway is a key constituent of China's high-speed railway network, linking the capital of Sichuan province and the capital of Guizhou province with a design speed of 250 kilometers per hour. Sections of the railway in Sichuan are already in use, while the whole line will be in operation by the end of this year. [Photo/Xinhua]