In order to the rising production costs, the subscription rates have been increased.
A. add up to
B. look up to
C. e up with
D. keep up with
网友回答
A. add up to
B. look up to
C. e up with
(答案→)D. keep up with
解析：D.考查动词短语意识辨析。 keep up with跟上。add up to合计，总计是；;look up to赞美，尊敬；本题中rates意为“价格，费用”。e up with 提出，找到，产生。
依据句意“为了跟上生产成本的上升，预定费已提高。”故选D