China's Winter Olympics gold medalist Yang Yang (Front) takes the G8811 high-speed train bound for Taizicheng Railway Station at Beijing North Railway Station in Beijing, capital of China, Dec. 30, 2019. The high-speed railway line connecting Beijing and Zhangjiakou in north China's Hebei Province went into service on Monday. Chongli railway, a branch line of the Beijing-Zhangjiakou high-speed railway, also came into service. (Xinhua/Peng Ziyang)