Ключевые слова: accessibility, barbed, barbed wire, blue, border, boundary, chemical, chemistry, concepts, control, dawn, desert, distance, dust, engineering, factory, fence, freedom, fuel, gas, horizon, horizontal, ideas, industry, manufacturing, metal, no people, oil, old, outdoor, petrochemical, pipeline, plant, pollution, power, prison, privacy, production, protection, refinery, risk, safety, security, sharp, sky, smoke, steel, track, twilight, wire,