Ключевые слова: air, aircraft, airline, airliner, airport, alert, alertness, attention, aviation, beach, beware, blue, breakdown, business, card, caution, concept, conceptual, danger, english, exclamation, flight, hand, hijacking, mark, message, note, plane, point, protect, protection, red, risk, road, safety, security, sign, sky, symbol, terrorism, tourism, traffic, transport, transportation, travel, triangle, warning, white,