Ключевые слова: aged, atomic, atomic energy, careful, caution, concrete wall, corrosion, danger, dangerous, dirty, emission, energy, environmental, flag, grunge, hazard, hazardous, material, mexico, national, nuclear, nuclear energy, pattern, plutonium, policy, politics, pollution, power, precaution, protection, radiation, radioactive, radioactive symbol, radioactivity, risk, rough, safety, surface, symbol, taxonomy, uranium, warning, weathered,