Largest high-speed train maintenance base in western China put into operation (3)

XI'AN, July 4, 2016 -- A mechanic clears the filter with a bullet train at the Xicheng high-speed train maintenance base in Xi'an, capital of northwest China's Shaanxi Province, July 4, 2016. Xicheng high-speed train maintenance base, which is the largest in western China, was put into operation recently. (Xinhua/Li Yibo)