The mask covers the nose and mouth. These are called half-mask air-purifying respirators.

这种面具将口鼻完全遮盖，称为半面罩过滤呼吸器。

youdao

The mask covers the nose and mouth. These are called half-mask air-purifying respirators.

这种面具将口鼻完全遮盖，称为半面罩过滤呼吸器。

youdao