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

Diesel engine air start system check valves are opened by （）

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

Using a file without a handle may result in （）

A purge recovery system is used in a centrifugal air conditioning or refrigeration system to （）

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

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

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

The shipboard oil pollution emergency plan will be invalid after （）

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