With new confirmed cases decreasing, the main COVID-19 battlefield has shifted to the ICUs. Dr. Zhou Ning is a cardiovascular physician from Tongji Hospital, Tongji Medical College, Huazhong University of Science & Technology. He did an ECMO operation for a critically ill patient in the ICU. "Sometimes life is fragile, sometimes life is strong. We have taken the first difficult step in better understanding COVID-19. In the future, the mortality rate will be further lowered. We will do our best," he said.