Ключевые слова: advice, ahead, arrow, attention, background, black, board, cables, careful, caution, danger, dangerous, electric, electrical, electricity, energy, fence, forbidden, hazard, high, icon, industry, inform, information, notice, old, power, protect, protection, risk, safety, security, short, sign, signal, signpost, supply, symbol, technology, text, thunder, triangle, voltage, warning, web, yellow,