Ключевые слова: 4k, alert, atomic, background, biological, caution, continent, danger, dangerous, design, earth, energy, geography, global, globe, graphic, hazard, icon, illustration, isolated, loop, map, nuclear, planet, plexus, poison, pollution, power, protection, radiation, radioactive, radioactivity, ray, red, risk, safety, science, sign, sphere, spinning, symbol, toxic, warning, world,