A medical staff guides citizens to do nucleic acid test for the prevention of COVID-19 pandemic in Suifenhe City, northeast China's Heilongjiang Province, Dec. 11, 2020. Chinese cities are tightening control measures to tackle the resurgence of the novel coronavirus through the winter months following recent sporadic spikes in confirmed cases. Anti-epidemic workers stand fast at their positions regardless of the heavy wind and cold weather to support those in need. (Xinhua/Xu Kaixin)
