Ключевые слова: background, blackboard, children, classroom, closed, closed school, college, crisis, curfew, danger, disease, education, epidemic, face mask, flu, health, high school, infected, information, learning, lesson, lessons, lockdown, locked, mask, online, outbreak, pandemic, prevention, quarantine, risk, school, school closed, school closure, schools, schools closed, sign, stay home, symbol, text, university, virus, word,