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
单项选择题 These include deck machinery such as mooring equipment, anchor handling equipment, cranes and （）.
单项选择题 The hand steering is a method by which the motion of the rudder is controlled with （）.
单项选择题 If a heavy sea strikes the rudder, the shock is transmitted through the tiller to （）.
