单项选择题
A.transmitter at the steering station and a receiver at the steering engine
B.reversible motor at the steering station geared to the steering pumps
C.small induction motor on the bridge which controls the redder through pulleys
D.variable displacement hydraulic pump driven by a reversible DC motor
单项选择题 In which of the areas listed would you expect to find the highest salt concentration in a flash evaporator?（）
单项选择题 The component of a refrigerating system in which the refrigerant vaporizes and absorbs heat is known as the （）.
单项选择题 The low pressure side of a refrigeration system is considered to exist from the （）.