单项选择题
A.The three moving vanes and the three fixed vanes form three pressure chambers
B.The three moving vanes and the three fixed vanes form six pressure chambers
C.The three moving vanes and the three fixed vanes form nine pressure chambers
D.The three moving vanes and the three fixed vanes form twelve pressure chambers
单项选择题 With reference to rules governing steering gear, which one of the following rules is incorrect? （）
单项选择题 With reference to operating a four-ram steering gear system under emergency conditions, which one of the following statements is incorrect?（）
单项选择题 With reference to a radial piston pump, which one of the following statements is false?（）