Photo taken on July 29, 2017 shows the construction site of Beijing-Zhangjiakou high-speed railway in Chongli District of Zhangjiakou City, north China's Hebei Province. Two years after Beijing and Zhangjiakou successfully bid to host the 2022 Winter Olympics, Chongli District, where most skiing events will be held, experienced a busy and colorful summer. (Xinhua/Yang Shiyao)
