单项选择题
A.The hydraulic pumps
B.Valves
C.Hydraulic cylinders
D.Hydraulic motors
单项选择题 The drive motor will have a brake arranged to fail-safe, i√eit will （） the load if power fails or machine is stopped.
单项选择题 （） are used for hauling in or letting out the wires which fasten the ship to the shore.
单项选择题 The drive motor will have a brake arranged to fail-safe, ieit will （） the load if power fails or machine is stopped.