Ключевые слова: air quality, asian, boy, carbon dioxide, caucasian, child, city, concept, coronavirus, covid19, danger, dark, education, elementary, face, flu, gas, gloomy, green, guy, healthy, house, jacket, male, mask, outdoor, pandemic, person, portrait, posing, protection, protective, pupil, quarantine, respiratory, safety, school, schoolboy, schoolchild, schoolgirl, sick, sky, student, teenage, uniform, urban, virus, warning, wearing, young,