Ключевые слова: abstract, background, barbed, barrier, black, boundary, breach, cage, chain, chainlink, connection, construction, crime, danger, design, effect, enclosure, escape, fence, forbidden, frame, freedom, gap, gate, grate, green, hole, horizontal, industry, iron, isolated, link, mesh, metal, metallic, notch, pattern, prison, protection, razor, safety, security, separation, shape, steel, system, technology, textured, wall, white, wire,