Ключевые слова: alone, assistance, attention, background, canada, concept, conservation, copyspace, danger, earth, exterior, forbidden, forest, hazard, help, ice, indication, information, metal, nature, noone, outdoor, panel, path, pole, prohibited, public, rectangle, red, restriction, risk, safety, sand, serene, sign, spring, summer, symbol, thin, trail, trees, urget, vacation, view, walk, warning,