单项选择题
If you are given the job of adding hydraulic fluid to a mooring winch, and are not certain as to the type of fluid to use, you should （）.
A.add fluid that is the same color as the fluid in the reservoir B.add turbine oil because it is always a good substitute C.add any oil that has the same viscosity as the hydraulic fluid D.check the winch manufacturers instruction book
单项选择题 The output volume of a positive fixed displacement pump can be changed only by （）.
单项选择题 An excessive charge of refrigerant in an air-cooled refrigeration system can cause （）.
单项选择题 When the steering gear is in operation, you should （）.
