Ключевые слова: architecture, backdrop, background, blue, bolt, building, business, connection, construction, duct, economy, employment, energy, engineering, equipment, factory, handle, industrial, industry, infrastructure, investment, line, machine, maintenance, material, municipal, municipality, oil, outdoors, part, pipe, pipeline, piping, plumber, power, pvc, residential, road, service, structure, supply, technology, tube, valve, water, white, work,