Thermostatic expansion valves can be adjusted for （）.

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

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

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

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

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

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

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

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

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