Ключевые слова: background, ban, barb, barbed, barbwire, barrier, blue, boarder, border, boundary, danger, disallow, fence, forbid, forbidden, free, freedom, frontier, gaol, guard, hazard, iron, jail, jeopardy, lesson, menace, metal, military, music, note, outlaw, peril, prison, prohibit, proscribe, protect, protection, razor, risk, safety, security, sharp, sky, steel, threat, wire,