Ключевые слова: adult, air, area, asian, background, chinese, city, concept, conceptual, contamination, cough, danger, disease, environment, eye, face, female, flu, girl, gray, grey, ill, influenza, japanese, lady, mask, medical, people, pollution, prevention, protect, protection, protective, safety, sick, smog, street, suffer, thai, traffic, transport, urban, virus, wearing, woman, young,