Ключевые слова: alert, atomic, background, beware, biology, black, caution, chemical, chemistry, chernobyl, dead, destruction, dirty, energy, green, hazard, hazardous, illustration, infected, infectious, mark, notice, nuclear, polution, power, protection, quarantine, radiation, radioactive, radioactivity, radioisotope, radium, ray, reactor, risk, sign, signs, substance, symbol, technology, texture, trefoil, triangle, uranium, war, warning, yellow,