A salinity indicator is used to determine the （）.

Thermostatic expansion valves can be adjusted for （）.

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?（）

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

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

Which of the following problems could cause the high pressure cutout switch to shut down the compressor in a refrigeration system?（）

Who is responsible for ensuring that someone is assigned to close the watertight doors in an emergency?（）

The amount of fluid friction or internal friction inherent in a mineral lubricating oil is reflected as a measure of its （）.

Low compressor head pressure in a refrigeration system can be caused by（）.

The output volume of a positive fixed displacement pump can be changed only by （）.