Staff members work on the construction site of the right track tunnel of the Huangjialing Tunnel in Linxia Hui Autonomous Prefecture, northwest China's Gansu Province, March 9, 2025. The right track tunnel of the Huangjialing Tunnel was drilled through on Sunday. The Huangjialing Tunnel, with a total length of 5,881 meters, is a key project of Lanzhou-Hezuo high-speed railway, a part of China's high-speed rail network that centers around eight main vertical lines linking the north and south and eight horizontal lines connecting the east and west. (Xinhua/Chen Bin)