单项选择题
On an electro-hydraulic steering gear, which of the listed devices will keep the rudder from over-traveling the bridge signal?（）
A.Rudder angle indicator B.Follow-up gear C.Electric transmitter D.Rudder angle limit switch
单项选择题 Rudder motion is prevented from exceeding the movement of the steering wheel by the（）
单项选择题 Air trapped in the hydraulic fluid of a steering system may be indicated by（）
单项选择题 The purging of air from an elector-hydraulic steering gear unit is necessary when（）
