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

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

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

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

One of the reasons that cause oil flowed from sludge outlet of a self-cleaning separator is（）

Which of the listed governor characteristics will greatly affect the load sharing relationship between paralleled diesel generators?（）

If two A.C.generators are to be operated in parallel, the load is distributed evenly by（）

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

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

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