Laborers work at the construction site of Dongshan Tunnel on No. 213 National Highway in Sunan Yugur Autonomous County, northwest China's Gansu Province, March 26, 2020. The construction of Dongshan Tunnel has fully resumed with strict measures to prevent the COVID-19 epidemic. With a total length of 3,639 meters and an average altitude of 3,850 meters, Dongshan Tunnel connects Qinghai and Gansu provinces along the No. 213 National Highway. (Xinhua/Fan Peishen)
