Ключевые слова: build, channel, circular, connect, construct, construction material, construction site, covid, development, duct, energy, engineering, factory, fix, group, heavy, hole, improvement, industrial, installing, job, layer, long, machine, maintenance, manufacture, material, no people, pipe, pipeline, plumbing, preparation, produce, production, ring, round, row, sanitary, second wave, site, stack, stock, structure, sunlight, supply, tool, tube, tunnel, underground, worker,