The mask is a kind of sanitary product, which is generally used to filter the air entering the mouth and nose by wearing it on the mouth and nose, so as to block harmful gases, smells and droplets from entering and leaving the mouth and nose of the wearer. It is made of gauze or paper, etc. Masks can filter the air entering the lungs to a certain extent. When respiratory infectious diseases are prevalent, and when working in dust and other polluted environment, wearing masks has a very good effect
