A bullet train runs on Zhengzhou-Xi'an high-speed railway line near Sanmenxia, central China's Henan Province, Jan. 16, 2010. China's high-speed railways now exceed 20,000 km in length with the opening of a line linking Zhengzhou in central China's Henan Province with Xuzhou in eastern Jiangsu Province on Sept. 10, 2016. The line connects the west with two major north-south lines, helping cut travel time between west and east in the country. [Xinhua]