两年了,终于得到这个结论了?
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RT @abc7newsbayarea
Studies are emerging that cloth masks are not as effective as surgical masks in preventing the spread of COVID. https://abc7news.com/covid-masks-face-coverings-n95/11425476/?ex_cid=TA_KGO_TW&taid=61d6099577a35f0001541b36&utm_campaign=trueAnthem%3A+Trending+Content&utm_medium=trueAnthem&utm_source=twitter
https://twitter.com/abc7newsbayarea/status/1478840266605871115