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

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

Using a file without a handle may result in （）

Which of the following items don’t belong to dock repair works?（）

Which of the diesel engine components listed increase air density and helps to improve engine operating efficiency?（）

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

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

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

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

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