单项选择题
It is important with all hydraulic systems to ensure that interlocking arrangements provided for pump or motor control levers are （） before the pump driving motor can be started.
A.in the pert position B.in the starboard position C.in the neutral position D.to be dismantled
单项选择题 Overload protection on hydraulic system is provided by the use of （）.
单项选择题 The most common forms of main drive used on deck auxiliaries are （）.
单项选择题 Mooring winches are often combined with （） units so that one prime mover drives both.
