它们比标准的外科口罩或有时建筑工人使用的防尘口罩要有效得多。

They are much more effective than the standard surgical masks or dust masks that are sometimes used by builders.

youdao

它们比标准的外科口罩或有时建筑工人使用的防尘口罩要有效得多。

They are much more effective than the standard surgical masks or dust masks that are sometimes used by builders.

youdao