戴口罩肯定管用，但不是百分之百。醫院裏ER，COVID病房/ICU醫護就是例子。不然醫院早就關門了。

來源: 老道於 2020-11-23 04:36:55 [舊帖] [給我悄悄話] 本文已被閱讀：次

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