单项选择题
A.excessive drive motor speed
B.excessive pump discharge pressure
C.too low of a tilting box angle
D.insufficient drive motor speed
单项选择题 Refrigerant enters the condenser as a （）.
单项选择题 An excessive amount of water is prevented from entering a vessel using a water lubricated stern tube bearing by the use of the （）.
单项选择题 Under normal conditions, the refrigerant enters the compressor in an operating refrigeration system as a （）.