Ключевые слова: background, broken, building, canalization, chamber, circle, city, construction, cover, danger, deep, design, dig, dirty, drain, drainage, gray, hard, hatch, hole, industrial, industry, iron, isolated, job, lid, maintenance, manhole, metal, old, open, outdoor, pipe, pit, processing, repair, road, sewage, sewer, sewerage, sign, street, tube, under, underground, unsecured, urban, warning, white, work,