单项选择题
A.an improper rudder response
B.hammering noises in the equipment or transmission lines
C.popping or sputtering noises
D.all the above
单项选择题 How can the chance of contaminating hydraulic fluid be decreased when working on hydraulic system?（）
单项选择题 In the design of hydraulic piping and equipment consideration is given to minimize turbulence in the hydraulic fluid, as this will cause（）
单项选择题 One function provided by a hydraulic accumulator is to（）