Construction workers wave hands to their workmates on the other side after the hole-through of Liaoxi Tunnel, the longest tunnel throughout the Beijing-Shenyang high-speed railway locating in Lingyuan City, northeast China's Liaoning province, Jan. 10, 2017. The 13.205 km tunnel constructed by China Railway 12th Bureau Group is also the longest one within northeast China by far. (Xinhua/Yang Qing)
