Ключевые слова: accident, advice, alberta, alert, attention, beware, bump, canada, care, careless, caution, cement, concrete, danger, depression, fall, floor, foot, gap, ground, hazard, information, injure, irregular, leg, liable, obstacle, orange, posted, public, rise, risk, rough, safety, sign, snag, stair, step, stumble, surface, trip, tumble, uneven, unsafe, walk, wall, warn, watch, white,