摘要
The coronavirus disease 2019(COVID-19)pandemic is undoubtedly the greatest challenge in peacetime facing the world for more than 100 years.No country is untouched with more than 100 million confirmed cases and over 2 million deaths as of January 28,2021(1),and the actual number of infections is probably closer to one billion as few countries had sufficient testing capacity to identify all cases,particularly throughout early 2020.
