Lao and Chinese workers and engineers from China Railway No. 2 Engineering Group work together to lay the tracks through the Ban Nong Khay Tunnel, in Vientiane Province, some 60 km to the north of capital Vientiane, Laos, on May 23, 2020. As each row of 14 cement sleepers laid smoothly across the Ban Nong Khay Tunnel at the prescribed distance and then the 500-meter long tracks settled on the sleepers precisely by the engineering train, China-Laos Railway's tracks has passed its first tunnel on Saturday. [Photo/Xinhua]