![Workers work at a construction site of the Beijing-Zhangjiakou high-speed railway in Zhangjiakou, north China\'s Hebei Province, June 11, 2018. The railway, connecting China\'s capital Beijing and Zhangjiakou of north China\'s Hebei Province, is designed at a speed of 350 kilometers per hour and is expected to be put into use at the end of 2019. (Xinhua/Yang Shiyao)](http://www.ecns.cn/hd/2018/06/12/7c8ac2a029b444b3ba698950ef390a7d.jpg)
Workers work at a construction site of the Beijing-Zhangjiakou high-speed railway in Zhangjiakou, north China's Hebei Province, June 11, 2018. The railway, connecting China's capital Beijing and Zhangjiakou of north China's Hebei Province, is designed at a speed of 350 kilometers per hour and is expected to be put into use at the end of 2019. (Xinhua/Yang Shiyao)
![Workers work at a construction site of the Beijing-Zhangjiakou high-speed railway in Zhangjiakou, north China\'s Hebei Province, June 11, 2018. The railway, connecting China\'s capital Beijing and Zhangjiakou of north China\'s Hebei Province, is designed at a speed of 350 kilometers per hour and is expected to be put into use at the end of 2019. (Xinhua/Yang Shiyao)](http://www.ecns.cn/hd/2018/06/12/26c5fdc4e42a4c758b38e163ef95a4cd.jpg)
Workers work at a construction site of the Beijing-Zhangjiakou high-speed railway in Zhangjiakou, north China's Hebei Province, June 11, 2018. The railway, connecting China's capital Beijing and Zhangjiakou of north China's Hebei Province, is designed at a speed of 350 kilometers per hour and is expected to be put into use at the end of 2019. (Xinhua/Yang Shiyao)
![Workers work at a construction site of the Beijing-Zhangjiakou high-speed railway in Zhangjiakou, north China\'s Hebei Province, June 11, 2018. The railway, connecting China\'s capital Beijing and Zhangjiakou of north China\'s Hebei Province, is designed at a speed of 350 kilometers per hour and is expected to be put into use at the end of 2019. (Xinhua/Yang Shiyao)](http://www.ecns.cn/hd/2018/06/12/9ec23d45c41f492cba7277efce677e36.jpg)
Workers work at a construction site of the Beijing-Zhangjiakou high-speed railway in Zhangjiakou, north China's Hebei Province, June 11, 2018. The railway, connecting China's capital Beijing and Zhangjiakou of north China's Hebei Province, is designed at a speed of 350 kilometers per hour and is expected to be put into use at the end of 2019. (Xinhua/Yang Shiyao)
![Workers work at a construction site of the Beijing-Zhangjiakou high-speed railway in Zhangjiakou, north China\'s Hebei Province, June 11, 2018. The railway, connecting China\'s capital Beijing and Zhangjiakou of north China\'s Hebei Province, is designed at a speed of 350 kilometers per hour and is expected to be put into use at the end of 2019. (Xinhua/Yang Shiyao)](http://www.ecns.cn/hd/2018/06/12/7276b525543342b8a533fcf3651a7593.jpg)
Workers work at a construction site of the Beijing-Zhangjiakou high-speed railway in Zhangjiakou, north China's Hebei Province, June 11, 2018. The railway, connecting China's capital Beijing and Zhangjiakou of north China's Hebei Province, is designed at a speed of 350 kilometers per hour and is expected to be put into use at the end of 2019. (Xinhua/Yang Shiyao)
![Workers work at a construction site of the Beijing-Zhangjiakou high-speed railway in Zhangjiakou, north China\'s Hebei Province, June 10, 2018. The railway, connecting China\'s capital Beijing and Zhangjiakou of north China\'s Hebei Province, is designed at a speed of 350 kilometers per hour and is expected to be put into use at the end of 2019. (Xinhua/Yang Shiyao)](http://www.ecns.cn/hd/2018/06/12/a16944ddfa3240d39f2a1247df038e4f.jpg)
Workers work at a construction site of the Beijing-Zhangjiakou high-speed railway in Zhangjiakou, north China's Hebei Province, June 10, 2018. The railway, connecting China's capital Beijing and Zhangjiakou of north China's Hebei Province, is designed at a speed of 350 kilometers per hour and is expected to be put into use at the end of 2019. (Xinhua/Yang Shiyao)