Ключевые слова: backgrounds, blue, color, concepts, counterweight, energy, equipment, exploration, fossil, fuel, gas, gasoline, industrial, industry, lever, machine, natural, nobody, oil, oilwell, outdoors, pipeline, pollution, power, prairie, prosperity, pulley, pump, reservoir, resource, retro, rig, scenics, silhouette, sky, steel, sunlight, tank, vintage, wealth,