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

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

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

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

Cold weather starting of a diesel engine may be made easier by（）

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

The main purpose of port State control is not to（）

（） is not installed on the main switchboar.

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