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

（）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?（）

As soon as a diesel engine has started, which of the listed engine operating parameters should be checked FIRST?（）

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

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

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

For a given exhaust gas boiler, what is the quantity of its evaporation mainly determined?（）

（） is not installed on the main switchboar.

By comparing the exhaust gas temperature of each cylinder, the operator can determine if the load is balanced throughout the engine. The device most commonly used is a（）