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

The rate of heat transfer from a hot region to a cold region is affected most by the （）.

The major source of chemical contaminants in hydraulic fluid is （）.

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

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

A salinity indicator is used to determine the （）.

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

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 （）.

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

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