Ключевые слова: bore, cave, cavern, dark, deep, dig, discovery, drill, drilling, engineering, equipment, excavate, excavation, exploration, export, extract, extraction, geology, gold, golden, hard, heavy, indoor, industrial, industry, inside, job, light, machine, machinery, mine, miner, mineral, modern, ore, resources, rock, stone, tool, tunnel, tunneling, underground, vechicle, vehicle, way, work,