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

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

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

“Insufficiency of manning or insufficiency of certification of seafarers” is an identification of a（）

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（）

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

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

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

The additional mark （）in the Classification Certificate for Machinery means propulsion apparatus is remotely controlled on the navigating bridge control station, and engine assembly control station is unmanned periodically.