Dong Huimin (R), a member of the medical team, says goodbye to her colleague before leaving for Wuhan, the epicenter of the coronavirus outbreak, in Lanzhou, northwest China's Gansu Province, Feb. 4, 2020. The second batch of a medical team comprised of 100 members from Gansu Province left for Wuhan in the early morning on Wednesday to aid the novel coronavirus control efforts there. (Photo by Du Zheyu/Xinhua)