[其他] Coronavirus could have been in US as early as mid-December 2019, CDC study says
The coronavirus pandemic may have started earlier than previously thought, according to scientists from the CDC.A study from government scientists published November 30 appears to confirm what some health experts have suggested, patients infected with COVID-19 were in the US before the beginning of 2020.https://www.thedenverchannel.com ... 2019-cdc-study-says