A grease gun is generally used to lubricate a （）.

Pitting in the suction areas of a centrifugal pump bronze impeller is usually caused by （）.

If the head pressure of a reciprocating refrigeration compressor is excessive, （）.

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 （）.

The usual symptoms of cavitation in a centrifugal pump is （）.

If the viscosity of the liquid being transferred remains constant as the discharge pressure increases, the rotary pump （）.

On tank vessels equipped with power operated cargo tank valves, the type of power operator most commonly used is （）.

Which of the following statements is correct concerning heat transfer?（）

When the steering gear is in operation, you should （）.

Which of the listed pumps is NOT a positive displacement pump?（）