A worker is seen at the construction site of the Great Wall station of the Beijing-Zhangjiakou high-speed railway line under the Badaling Great Wall area in Beijing, capital of China, Aug. 8, 2017. Beijing-Zhangjiakou high-speed railway, a major transportation project for the 2022 Olympic and Paralympic Winter Games, is expected to be finished by the end of 2019. (Xinhua/Li Wen)
