单项选择题
A.Hydraulic pumps B.Valve C.Hydraulic cylinders D.Hydraulic motors
Among the basic categories of equipment, which of the f...
单项选择题Among the basic categories of equipment, which of the following are used to convert mechanical into hydraulic energy?（）
A.The hydraulic pumps B.Valves C.Hydraulic cylinders D.Hydraulic motors
The drive motor will have a brake arranged to fail-safe...
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.
A.cast B.put C.hold D.let out
（） are used for hauling in or letting out the wires whi...
单项选择题（） are used for hauling in or letting out the wires which fasten the ship to the shore.
A.Cargo winches B.Mooring winches C.Windlasses D.Cargo hatches
