A salinity indicator is used to determine the （）.

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

Which of the problems listed would came the discharge temperature of an R-12 refrigeration compressor to increase?（）

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

A gradual decrease in the discharge pressure of an operating hydraulic pump can be caused by （）.

The rate of heat transfer between the hot and cold fluids passing through a shell-and-tube type heat exchanger will （）.

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

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

An increasing head pressure in a refrigeration system, without any corresponding change in the cooling water inlet temperature, would probably be caused by （）.

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