Bai Zhiyong, a senior surveyor with China Railway First Group Co., Ltd., measures a railway tunnel at the construction site in Longmen Township of Hancheng City, northwest China's Shaanxi Province, March 28, 2017. Bai is a delegate to attend the 19th Communist Party of China (CPC) National Congress. In the past 18 years, Bai and his team accurately measured high-speed rail track of 2,200 kilometers long, accounting for one-tenth of China's total. (Xinhua/Hou Ruobin)