Chen Zhi shows his plasma donation certificate at a blood donation vehicle in Wuhan, central China's Hubei Province, March 12, 2020. After undergoing a 14-day quarantine for medical observation as a cured COVID-19 patient, Chen Zhi and other 84 patients were permitted to return home from a medical treatment station in Wuhan Vocational College of Software and Engineering. Although Chen missed his family profoundly since he has been away from home for more than a month, Chen couldn't wait to fulfill the promise he made with other two patients during quarantine, to donate plasma in a bid to help other patients fighting against COVID-19. (Xinhua/Fei Maohua)