单选题 The steadily rising cost of labor on the waterfront has greatly increased the cost of shipping cargo by water.
【正确答案】 A
【答案解析】[解析] 本题大意：码头工人劳动力价格的持续上涨极大地提高了从水路运货的成本。画线词steadily：稳固地，持续地，与选项中的gradually意义一致，故答案为A。