During the diesel engine running, the water level of F.W expansion tank should normally kept in the （） level of glass tube.

The flash point of a residual fuel oil should be used to determine the highest temperature to which oil may be heated（）

Thermostatic steam pressure reducing valves are used in the fuel oil service system to control the（）

The cetane rating of diesel fuel is an indication of the （）

Using a file without a handle may result in （）

Refrigerant entering the compressor of a refrigeration system should be in which of the following conditions?（）

The Port State Control officer may witness a fire drill carried out by the crew assigned to these duties on the（）

Flame failure in an automatically fired auxiliary boiler can from a/an （）

One of the reasons that cause oil flowed from sludge outlet of a self-cleaning separator is（）

（）connectors hold best if a wire is accidentally pulled or a connection becomes loose.