单项选择题
A.changing over to hand pump operation
B.engaging the trick wheel
C.the system has been filled with new oil
D.the rudder angle indicator does not match the helm position
单项选择题 If a severe leak develops in the electro-hydraulic steering gear unit is necessary when（）
单项选择题 A power failure in the hydraulic system of a compact type steering gear would cause the rudder to（）
单项选择题 According to Regulations, a power driven auxiliary steering gear for a vessel capable of a 12 knot service speed, must be able to meet the rudder movement requirements at which of the minimum vessel speeds listed below?（）