A bullet train is seen at Ningqiang South Railway Station of Xi'an-Chengdu high-speed railway during a test in northwest China's Shaanxi Province, Oct. 26, 2017. The Xi'an-Chengdu line is China's first rail route to run through the Qinling Mountains, which are the natural boundary between north and south China. It will begin operation on Dec. 6. [Photo/Xinhua]