File photo taken on June 20, 2006 shows a train running on the Qinghai-Tibet Railway past a farm range in southwest China's Tibet Autonomous Region. The Qinghai-Tibet Railway turns 10 on July 1, 2016. The 1,956-kilometer-long railway, which began service in July 2006, is the world's highest and longest plateau railroad and also the first railway connecting the Tibet Autonomous Region with other parts of China. Ecological protection measures taken during and after the construction of the railway have ensured it was built as "a green railway". Noting that environmental pollution has been brought under effective control, it said the alpine vegetation ecosystem has been effectively protected, the permafrost environment has been stable for years, the eco-function regions have been doing well and the plateau landscape remains intact. (Xinhua/Chogo)

Photo taken on June 21, 2016 shows a train running on the Qinghai-Tibet Railway through the Northern Tibet Grassland, southwest China's Tibet Autonomous Region. The Qinghai-Tibet Railway turns 10 on July 1, 2016. The 1,956-kilometer-long railway, which began service in July 2006, is the world's highest and longest plateau railroad and also the first railway connecting the Tibet Autonomous Region with other parts of China. Ecological protection measures taken during and after the construction of the railway have ensured it was built as "a green railway". Noting that environmental pollution has been brought under effective control, it said the alpine vegetation ecosystem has been effectively protected, the permafrost environment has been stable for years, the eco-function regions have been doing well and the plateau landscape remains intact. (Xinhua/Purbu Zhaxi)

File hoto taken on Sept. 28, 2014 shows a train running on the Nagqu section of the Qinghai-Tibet railway, southwest China's Tibet Autonomous Region. The Qinghai-Tibet Railway turns 10 on July 1, 2016. The 1,956-kilometer-long railway, which began service in July 2006, is the world's highest and longest plateau railroad and also the first railway connecting the Tibet Autonomous Region with other parts of China. Ecological protection measures taken during and after the construction of the railway have ensured it was built as "a green railway". Noting that environmental pollution has been brought under effective control, it said the alpine vegetation ecosystem has been effectively protected, the permafrost environment has been stable for years, the eco-function regions have been doing well and the plateau landscape remains intact. (Xinhua/Wang Song)

File photo taken on July 1, 2006 shows the train coded "Zang (Tibet) 2" running on the Qinghai-Tibet Railway across the Lhasa River after leaving the Railway Station of Lhasa, capital of southwest China's Tibet Autonomous Region. The Qinghai-Tibet Railway turns 10 on July 1, 2016. The 1,956-kilometer-long railway, which began service in July 2006, is the world's highest and longest plateau railroad and also the first railway connecting the Tibet Autonomous Region with other parts of China. Ecological protection measures taken during and after the construction of the railway have ensured it was built as "a green railway". Noting that environmental pollution has been brought under effective control, it said the alpine vegetation ecosystem has been effectively protected, the permafrost environment has been stable for years, the eco-function regions have been doing well and the plateau landscape remains intact. (Xinhua/Sonam Norbu)

File photo taken on July 9, 2013 shows a freight train running on the Qinghai-Tibet Railway past the Kunlun Mountain in northwest China's Qinghai Province. The Qinghai-Tibet Railway turns 10 on July 1, 2016. The 1,956-kilometer-long railway, which began service in July 2006, is the world's highest and longest plateau railroad and also the first railway connecting the Tibet Autonomous Region with other parts of China. Ecological protection measures taken during and after the construction of the railway have ensured it was built as "a green railway". Noting that environmental pollution has been brought under effective control, it said the alpine vegetation ecosystem has been effectively protected, the permafrost environment has been stable for years, the eco-function regions have been doing well and the plateau landscape remains intact. (Xinhua/Hou Deqiang)

File photo taken on July 21, 2006 shows local children waving to a train running on the Qinghai-Tibet Railway in Duilong Deqing County of southwest China's Tibet Autonomous Region. The Qinghai-Tibet Railway turns 10 on July 1, 2016. The 1,956-kilometer-long railway, which began service in July 2006, is the world's highest and longest plateau railroad and also the first railway connecting the Tibet Autonomous Region with other parts of China. Ecological protection measures taken during and after the construction of the railway have ensured it was built as "a green railway". Noting that environmental pollution has been brought under effective control, it said the alpine vegetation ecosystem has been effectively protected, the permafrost environment has been stable for years, the eco-function regions have been doing well and the plateau landscape remains intact. (Xinhua/Chogo)

File photo taken on May 28, 2016 shows a freight train running on the Nagqu section of the Qinghai-Tibet Railway, southwest China's Tibet Autonomous Region. The Qinghai-Tibet Railway turns 10 on July 1, 2016. The 1,956-kilometer-long railway, which began service in July 2006, is the world's highest and longest plateau railroad and also the first railway connecting the Tibet Autonomous Region with other parts of China. Ecological protection measures taken during and after the construction of the railway have ensured it was built as "a green railway". Noting that environmental pollution has been brought under effective control, it said the alpine vegetation ecosystem has been effectively protected, the permafrost environment has been stable for years, the eco-function regions have been doing well and the plateau landscape remains intact. (Xinhua/Jigme Dorje)

File photo taken on Aug. 1, 2015 shows a five-year-old girl viewing plateau scenery while taking a train on Lhasa-Xigaze railway line, the first extention line of the Qinghai-Tibet railway, in southwest China's Tibet Autonomous Region. The Qinghai-Tibet Railway turns 10 on July 1, 2016. The 1,956-kilometer-long railway, which began service in July 2006, is the world's highest and longest plateau railroad and also the first railway connecting the Tibet Autonomous Region with other parts of China. Ecological protection measures taken during and after the construction of the railway have ensured it was built as "a green railway". Noting that environmental pollution has been brought under effective control, it said the alpine vegetation ecosystem has been effectively protected, the permafrost environment has been stable for years, the eco-function regions have been doing well and the plateau landscape remains intact. (Xinhua/Liu Dongjun)

File photo taken on July 1, 2006 shows the passenger train coded "Qing 1" passing the Tanggula Mountain Pass with an altitude of 5,072 meters above sea level, the highest of world's railway, in southwest China's Tibet Autonomous Region. The Qinghai-Tibet Railway turns 10 on July 1, 2016. The 1,956-kilometer-long railway, which began service in July 2006, is the world's highest and longest plateau railroad and also the first railway connecting the Tibet Autonomous Region with other parts of China. Ecological protection measures taken during and after the construction of the railway have ensured it was built as "a green railway". Noting that environmental pollution has been brought under effective control, it said the alpine vegetation ecosystem has been effectively protected, the permafrost environment has been stable for years, the eco-function regions have been doing well and the plateau landscape remains intact. (Xinhua/Gaesang Dawa)

File photo taken on June 7, 2016 shows Tibetan antelopes moving near the Qinghai-Tibet railway in Hoh Xil, northwest China's Qinghai Province. The Qinghai-Tibet Railway turns 10 on July 1, 2016. The 1,956-kilometer-long railway, which began service in July 2006, is the world's highest and longest plateau railroad and also the first railway connecting the Tibet Autonomous Region with other parts of China. Ecological protection measures taken during and after the construction of the railway have ensured it was built as "a green railway". Noting that environmental pollution has been brought under effective control, it said the alpine vegetation ecosystem has been effectively protected, the permafrost environment has been stable for years, the eco-function regions have been doing well and the plateau landscape remains intact. (Xinhua/Wu Gang)

File hoto taken on July 20, 2006 shows a train running on the Qinghai-Tibet Railway near Lake Cona in southwest China's Tibet Autonomous Region. The Qinghai-Tibet Railway turns 10 on July 1, 2016. The 1,956-kilometer-long railway, which began service in July 2006, is the world's highest and longest plateau railroad and also the first railway connecting the Tibet Autonomous Region with other parts of China. Ecological protection measures taken during and after the construction of the railway have ensured it was built as "a green railway". Noting that environmental pollution has been brought under effective control, it said the alpine vegetation ecosystem has been effectively protected, the permafrost environment has been stable for years, the eco-function regions have been doing well and the plateau landscape remains intact. (Xinhua/Chogo)

Photo taken on June 26, 2016 shows a train running on the Qinghai-Tibet Railway through a wetland of Northern Tibet, southwest China's Tibet Autonomous Region. The Qinghai-Tibet Railway turns 10 on July 1, 2016. The 1,956-kilometer-long railway, which began service in July 2006, is the world's highest and longest plateau railroad and also the first railway connecting the Tibet Autonomous Region with other parts of China. Ecological protection measures taken during and after the construction of the railway have ensured it was built as "a green railway". Noting that environmental pollution has been brought under effective control, it said the alpine vegetation ecosystem has been effectively protected, the permafrost environment has been stable for years, the eco-function regions have been doing well and the plateau landscape remains intact. (Xinhua/Purbu Zhaxi)