The number of confirmed cases of COVID-19 all over the world has increased rapidly. As of April 4, the number of confirmed cases has exceeded 1 millio…
资讯
目前市场上的口罩主要分为三类，一类是过滤效率较低的棉布口罩；一类是过滤效率稍高、无纺布材质的一次性医用口罩；一类是过滤效率较高的防护口罩（KN95、KN99等）。
As the outbreak of the COVID-19, face masks became a heated topic to everyone. It disturbs millions of people that the medical supplies fall into the …