Ключевые слова: background, caution, chemical, city, connection, construction, danger, do, energy, environment, equipment, forbid, forbidden, fuel, gas, hand, handle, icon, industrial, industry, label, many, metal, metallic, natural, no, oil, outside, palm, people, petroleum, pipeline, power, prohibited, prohibition, red, restriction, safety, sign, silver, steel, stop, structure, symbol, system, technology, touch, warning, white,