单项选择题
A.principle B.medium C.instruction D.voltage
In a general cargo crane, three principal movements are...
单项选择题In a general cargo crane, three principal movements are （）； （）； （）.
A.hoisting；luffing；slewing B.lifting；raising；lowering C.rotating；raising；handling D.hosting；lowering；moving
A warp end may be fitted for operating the derrick topp...
单项选择题A warp end may be fitted for operating the derrick topping wire which adjusts the derrick （）.
A.length B.slack C.height D.rotation direction
These include deck machinery such as mooring equipment,...
单项选择题These include deck machinery such as mooring equipment, anchor handling equipment, cranes and （）.
A.boilers B.bow thrusters C.stabilizers D.hatch covers
