A medical worker demonstrates how to correctly use masks for prevention in Wuying, a village of Miao ethnic group on the border of south China's Guangxi Zhuang Autonomous Region and southwest China's Guizhou Province, Jan. 26, 2019. A medical aid team on the prevention and control of the novel coronavirus outbreak came to Wuying village. All group activities scheduled for the Spring Festival are cancelled according to the local authority. (Xinhua/Huang Xiaobang)