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

When does auxiliary burner of incinerator put into operation? （）Ⅰ. start incinerator when it is coldⅡ. the sludge for dealing with is littleⅢ. the sludge for dealing with is largeⅣ. the water and impurity in sludge are too muchⅤ. the temperature in incinerator is lowⅥ. dealing with little solid rubbish

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

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

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

Using a file without a handle may result in （）

The condensers located in various stages of a flash evaporator are cooled by（）

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

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

If separating effect is not good, which measure should be taken （）