Aerial photo taken on Dec. 15, 2019 shows theSaishiteng Tunnel along the Dunhuang-Golmud railway in northwest China. A new railway linking Dunhuang city, northwest China's Gansu Province, and Golmud city, northwest China's Qinghai Province, fully opened on Wednesday, according to China Railway. The 671-km route is an important connecting line between the Qinghai-Tibet Railway and the Lanzhou-Xinjiang Railway. It allows trains to run at 120 km per hour, said the company. (Xinhua/Zhang Long)