Ключевые слова: abstract, background, barb, barbed, barbwire, barrier, blue, border, boundary, closeup, cloud, concept, danger, day, defend, defense, fence, forbidden, freedom, green, industrial, invade, iron, jail, line, metal, military, obstacle, old, pattern, prison, private, protect, protection, razor, rusty, safe, safety, security, sharp, sky, steel, summer, sun, symbol, territory, travel, tree, war, wire,