Qinghai-Tibet railway makes a difference in 7-year operation (3/3)

A freight train runs on the permafrost region of the Qinghai-Tibet Railway in northwest China's Qinghai Province July 9, 2013. Within seven years after its operation, the Qinghai-Tibet Railway, the longest and highest railway in the world, has carried nearly 64 million passengers and 300 million tonnes of goods. (Xinhua/Hou Deqiang)