Ключевые слова: art, background, brown, bucket, carbon, coal, colorful, digging, dioxide, earth, ecology, energy, environmental, excavator, fossil, fuel, germany, giant, ground, hole, landscape, large, lignite, machine, mine, mining, mover, mullock, nice, north, open, opencast, patron, pit, pollution, power, rhine, risk, soil, structures, westphalia, wheel,