单项选择题
Which one of the following is not generally recognized as one constitute of bilge water?（）
A.Oil leaking from tanks inside engine room B.Engine room cleaning water C.Water leaking from the separator sludge tank D.Sewage
单项选择题 A centrifugal compressor’s purge recovery unit（）
单项选择题 The device, which is installed in the compressor suction line to prevent liquid from entering the compressor when hot gas defrosting, is called a（）
单项选择题 The humidity of the atmosphere can be determined by the use of the（）
