Owing to the increasing cost of raw materials,we may not able to

Owing to the increasing cost of raw materials,we may not able to maintain the current price level, _______ alone to lower our prices.
【正确答案】：let
【题目解析】：[解析]句意：由于原材料价格持续上涨，原价我们尚且不能维持，更不用说压低价格了。 let alone表示 “更不用说”。