Ключевые слова: backdrop, ballast, bouldering, building, building activity, building material, construction, construction industry, construction material, construction site, copy space, expanse, floor, flooring, foundation, granita, gravel, ground, hard, heap, industrial, industry, macadam, masonry, material, mineral, natural, outdoors, paving stone, pebble, pebbles, road, roadbed, rock, rough, stability, stack, stacks, stone, stone material, stones, surface level,