Passengers goes through automatic ticket-checking system to board train K7039 at Harbin Railway Station in Harbin, northeast China's Heilongjiang Province, Jan. 6, 2021. Train K7039, connecting Harbin, capital of Heilongjiang, and Mohe, China's northernmost city in Heilongjiang, runs a distance of 1,223 kilometers during the over 16-hour trip. Many passengers visit Mohe in winter to experience the extreme cold weather. The outside temperature drops to about minus 40 degrees Celsius while inside the train it remains over 20 degrees Celsius. (Xinhua/Xie Jianfei)
