Aerial photo taken on May 18, 2017 shows a zigzag asphalt road leading to Mount Qomolangma in southwest China's Tibet Autonomous Region. Infrastructure has been improved in Tibet, as a comprehensive transportation network composed of highways, railways and air routes has been formed. (Xinhua/Purbu Zhaxi)

Photo taken on Oct. 16, 2018 shows construction site of Lhasa-Nyingchi railway in southwest China's Tibet Autonomous Region. Infrastructure has been improved in Tibet, as a comprehensive transportation network composed of highways, railways and air routes has been formed. (Xinhua/Purbu Zhaxi)

Performers give a dance performance beside a plane of the Tibet Airlines which prepares to take off at the Lhasa Gonggar Airport, southwest China's Tibet Autonomous Region, July 26, 2011. Infrastructure has been improved in Tibet, as a comprehensive transportation network composed of highways, railways and air routes has been formed. (Xinhua/Chogo)