（）are used to digest the sewage to produce innocuous sludge in a biological sewage treatment plant.

If two A.C.generators are to be operated in parallel, the load is distributed evenly by（）

The treatment of the fuel oils involves storage, heating, filtering and（）

To shut down a diesel engine after it exceeds the set maximum speed，which type of device listed should be used?（）

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

To proceed to the assistance of a ship in distress is（）

Under MARPOL Code the ship to which it applies has to carry （）

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

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

Which one is NOT the ‘clear grounds’ for a more detailed inspection?（）