Ключевые слова: ahead, alarm, alert, attention, background, bad, beware, business, caution, challenge, concept, danger, dangerous, desert, hill, nobody, not, object, park, police, post, progress, protect, protection, restricted, risk, road, roadsign, safety, sign, slope, stop, street, threat, traffic, transportation, travel, tree, under, violence, warn, word, work, yellow,