Ключевые слова: background, bar, barricade, barrier, block, border, boundary, bulwark, chain, construction, danger, dark, design, element, fence, garden, grass, grate, icon, iron, isolated, line, link, metal, nature, parapet, picket, pole, protection, rail, railing, road, safety, security, sign, stockade, stop, street, symbol, texture, traffic, warning, web, white, wire, work, yellow,