Ключевые слова: car, cave, cavern, cross, deep, dig, digger, discovery, driving, engineering, equipment, excavate, excavated, exploration, export, extract, gallery, geology, gold, industrial, industry, inside, lights, load, machine, machinery, mine, mineral, moving, ore, rock, safety, stone, subterranean, transportation, truck, tunnel, tunneling, turn, turning, underground, vehicle, work, working,