英语语法分析

Chin cup helps to position the facepiece properly.

下巴杯面罩有助于正确位置。

Disposable or filtering facepiece respirators are a type of respiratory protection in which the entire respirator facepiece is comprised of filter material.

随弃式呼吸防护口罩是呼吸器的一种，呼吸防护口罩的面罩整体都是由过滤材料构成的。

Purchasing reusable respirators also may reduce or eliminate the impact of potential shortages of filtering facepiece respirators and may be more cost effective over the duration of the pandemic.

购买可更换式呼吸器不仅可以降低或消除随弃式呼吸防护口罩因货源不足造成的潜在影响，而且在流感爆发期间使用时还会更经济。