Nurses test medical equipment at an isolated ward of a hospital complex building used for infectious disease prevention in Yinchuan, northwest China's Ningxia Hui Autonomous Region, Feb. 21, 2020. Designated for the novel coronavirus prevention and control, the complex building, an expansion project of the Fourth People's Hospital of Ningxia, was finished in 15 days and delivered on Friday. (Xinhua/Wang Peng)