Construction on the last two(Mainling Tunnel and Zagar Tunnel)of the 47 tunnels pertaining to a railway linking Lhasa and Nyingchi in Tibet Autonomous Region has been completed on April 7.Lhasa-Nyingchi Railway is a section of Sichuan-Tibet Railway,which is the first electrified railway in Tibet with a total length of 435 km and a designated speed of 160 km per hour.It is expected to be completed by the end of 2020,and start operation in 2021.