Workers from China Railway Electrification Engineering Group install ratchet wheel frames between Nyingchi and Kangar on the Lhasa-Nyingchi section of the Sichuan-Tibet Railway in southwest China's Tibet autonomous region, April 2, 2020. Construction of the Sichuan-Tibet Railway, the second railway to go into Tibet, has been making steady progress. Recently, 47 tunnels along the Lhasa-Nyingchi section of the railway have been bored, laying a solid foundation for the operation of the section. (Photo/Xu Yuyao)