smog 雾霾

　　mask 口罩、面膜

　　A mask is an object normally worn on the face, typically for protection, disguise（伪装）, performance, or entertainment.

　　gas mask 防毒面

　　oxygen mask 氧气面罩

　　air purifier /?pj?r?fa??r/ 空气净化器

　　An air purifier is a device which removes pollution from the air in a room.

　　fire extinguisher 灭火器 /?k?st??ɡw???r/