Ключевые слова: blue, brown, building, business, conservation, construction, crane, cylinder, digging, ditch, energy, engineering, environment, environmental, equipment, finance, fossil, freight, fuel, gas, gasoline, generation, industry, iron, line, machine, metal, natural, nature, oil, oilfield, pipe, pipeline, pollution, power, removing, single, sky, steel, supply, technology, transportation, trench, tube, wealth, working,