Ключевые слова: 3d, background, bone, carbon, cartoon, charcoal, coal, combustion, concept, design, diagram, dioxide, earth, electric, energy, factory, flat, fluid, formation, fossil, fuel, gas, geology, ground, heat, house, icon, illustration, industry, isometric, lump, methane, miner, natural, oil, petroleum, plant, pollution, power, pressure, process, production, soil, station, technology, timeline, underground, well,