People walk near the Songhua River in Jilin City, northeast China's Jilin Province, Jan. 12, 2018. The Jilin section of the Songhua River is unfreezed despite a freezing cold temperature of minus 20 degrees Celsius. It is because the upper reach Fengman Hydropower Station has been injecting water of four degrees Celsius into the river. (Xinhua/Xu Chang)