单项选择题
An important consideration in selecting a lubricating oil for use in a refrigeration compressor is for the oil to （）
A.have a high viscosity index B.mix readily with refrigerant C.have a high freezing point D.have a low pour point
单项选择题 Properties of a good refrigeration oil include（）
单项选择题 Proper filtering and straining of diesel fuel is important because the（）
单项选择题 Which factor determines the ring dam size for a fuel oil, tubular bowl type, centrifugal purifier?（）
