冷冻系数是冷冻剂从被冷冻物质中所取出的热量Q（冷冻量）与所消耗的压缩机械功N的（）。
A、比值
B、差
C、积
D、和
参考答案：A
A senior firefighter said it was _____ that the fire, which broke out at midnight, was caused by
someone on purpose. [ ]
A. possibly
B. likely
C. probably
D. obviously
商品调价，不得擅自降级降价或（）
A.减少库存
B.提及提价
C.扩大销售
D.退回厂家
