Photo taken on May 28, 2016 shows the Nagqu section of the Qinghai-Tibet railway, southwest China's Tibet Autonomous Region. The 1,956-kilometer-long Qinghai-Tibet railway, the world's highest altitude train line, has been put into service for 10 years. It links Lhasa, capital of southwest China's Tibet Autonomous Region, and Xining, capital of Qinghai Province in northwest China. [Photo: Xinhua]