Ключевые слова: accident, area, attack, attention, background, biohazard, careful, caution, concept, construction, danger, dangerous, disease, electricity, graphic, hazard, high, icon, idea, illustration, infected, infection, isolated, keep, message, notice, nuclear, poster, print, protect, ray, ribbon, risk, rubber stamp, safety, security, sign, situation, stamp, sticker, stop, sunbeam, symbol, type, virus, voltage, warning, work, zone,