A worker assembles an axle of an electric vehicle at the Dongming Company of Shaanxi Automotive Group in Tongchuan City, northwest China's Shaanxi Province, June 6, 2018. Tongchuan, once a manufacturing base for coal mining industry and cement production, used to suffer from environment pollutions. The local government has focused on sustainable development in the recent years and helped industries transform to grasp more opportunities. (Xinhua/Li Yibo)