One cause of high head pressure occurring in a refrigeration system can be （）.

Thermostatic expansion valves can be adjusted for （）.

A salinity indicator is used to determine the （）.

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 （）.

If the relief valve on the discharge side of a hydraulic pump lifts, the cause could be （）.

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

Heavy wear in a particular area of the inner circumference of a packing ring may be caused by （）.

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

The temperature differential occurring between the inlet temperature of the fluid to be cooled and the outlet temperature of the cooling medium in a shell-and-tube heat exchanger is greatest in which of the flow designs listed?（）

When a refrigeration compressor has developed a high head pressure as a result of a refrigerant overcharge, you should （）.