Ключевые слова: ancient, blue, brown, building, clouds, cloudsky, construction, czech, digging, earth, ecology, energy, environmental, equipment, excavator, factory, fuel, heavy, hole, home, house, industry, landscape, large, machine, magnesium, mine, mineral, mining, old, open, ore, pit, pollution, power, quarry, republic, resource, rock, sand, sky, slope, strip, technology, tree, view,