Welders examine facade of steel rails before welding at Xiaolizhuang Welding Base of Mechanical Works Section of Zhengzhou Railway Bureau in Zhengzhou, capital of central China's Henan Province, May 4, 2017. A total of 135 welders at the base are working to weld 100-meter-long steel rails into 500-meter-long rails for high-speed railway. Since 2008, the base has provided rail tracks for China's high-speed railway with a total length of over 2,000 kilometers. (Xinhua/Li An)
