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單項(xiàng)選擇題

Among the basic categories of equipment, which of the following are used to allow the hydraulic energy to be controlled?（）

A.hydraulic pumps
B.valves
C.hydraulic cylinders
D.hydraulic motors

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單項(xiàng)選擇題

（） are used for cargo handling.

A.Cranes
B.Mooring winches
C.Windlasses
D.Foreman

單項(xiàng)選擇題

In a hydraulic system, （） are used to protect the system from over pressure.

A.stop valves
B.check valves
C.safety valves
D.reducing valves