Train driver Xu Rui controls a high-speed train during a trial operation of the Yinchuan-Xi'an high-speed railway, Dec. 12, 2020. The Yinchuan-Xi'an high-speed railway is about to be put into service. (Xinhua/Feng Kaihua)

Chief conductor Dong Fang patrols on a high-speed train during a trial operation of the Yinchuan-Xi'an high-speed railway, Dec. 12, 2020. The Yinchuan-Xi'an high-speed railway is about to be put into service. (Xinhua/Chen Bin)

A bullet train stands at Huianbu station during a trial operation of the Yinchuan-Xi'an high-speed railway, Dec. 12, 2020. The Yinchuan-Xi'an high-speed railway is about to be put into service. (Xinhua/Chen Bin)

Aerial photo taken on Dec. 12, 2020 shows a bullet train running across Mafanggou grand bridge during a trial operation of the Yinchuan-Xi'an high-speed railway. The Yinchuan-Xi'an high-speed railway is about to be put into service. (Xinhua/Chen Bin)