Passengers show tickets on the train G2021, the first train of the high speed railway from Zhengzhou to Lanzhou, July 9, 2017. The high speed railway linking Zhengzhou of central China's Henan and Lanzhou of northwest China's Gansu started operation formally on Sunday. The shortest travel time of the railway between Zhengzhou and Lanzhou was shortened to less than five hours. (Xinhua/Li An)