单项选择题
A.the manual trick wheel is engaged for steering
B.the variable stroke pump is off stroke
C.a rudder order is given by the control system
D.an electric power system failure occurs at the steering gear
单项选择题 Saltwater is typically provided to a refrigeration system to （）.
单项选择题 Which of the listed operations will cause an automatically controlled refrigeration compressor to restart?（）
单项选择题 In an electro-hydraulic steering gear system, when will the variable displacement pump be placed on stroke?（）