双层30%口罩只能阻挡51%，要达到95%阻挡率要8个。

来源: 周老大于 2021-11-13 09:41:31 [博客] [旧帖] [给我悄悄话] 本文已被阅读：次

WENXUECITY.COM does not represent or guarantee the truthfulness, accuracy, or reliability of any of communications posted by other users.

双层30%口罩只能阻挡51%， 要达到95%阻挡率要8个。