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

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

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

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（）

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

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

The main purpose of port State control is not to（）

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

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

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