Ключевые слова: alert, bacteria, ban, biohazard, biology, caution, closed, concept, contamination, coronavirus, covid 19, covid19, crisis, dangerous, death, disease, epidemic, flu, global, hazard, illness, infection, influenza, information, limit, mask, medical, medicine, outbreak, outdoor, pandemic, pillar, pneumonia, prevention, protection, quarantine, respiratory, road, road sign, roadsign, sign, signal, stop, stop sign, symbol, traffic sign, virus, warning, world,