A bullet train runs on a bridge of Chongqing-Guiyang Railway in southwest China's Chongqing Municipality, Jan. 9, 2018. A railway connecting two major cities in southwest China, Chongqing and Guiyang is under trial run. Designed for passenger trains running at a speed of 200 kilometers per hour, the railway will improve traffic between China's southwest and northwestern, eastern, southern areas. (Xinhua/Liu Chan)