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

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（）

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

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

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

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

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

The cetane rating of diesel fuel is an indication of the （）

The flash point of a residual fuel oil should be used to determine the highest temperature to which oil may be heated（）

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