File photo taken on June 22, 2016 shows workers working near Tanggula Station of 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.[Photo/Xinhua]