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

A salinity indicator is used to determine the （）.

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

If the thermal bulb of an expansion valve is incorrectly placed at the center of the coil instead of the end, it will （）.

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

The general purpose of a heat exchanger is to （）.

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 （）.

An excessive charge of refrigerant in an air-cooled refrigeration system can cause （）.

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

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