Ключевые слова: aqueduct, background, cement, circular, concrete, construction, culvert, cylinder, cylindrical, dirt, ditch, drain, drainage, drainpipe, ducts, flow, grass, grime, industrial, industry, lawn, nature, park, pipe, pipeline, plumbing, round, sewage, sewer, soil, spring, sun, tube, tunnel, underground, water, waterspout, waterway, weed,