When starting a reciprocating pump, the inlet valve should be （）.

A、closed

B、opened fully

C、cracked open

D、partly open

One end of a cylinder for a medium or high-speed diesel engine is sealed by the piston and rings, the other end is sealed by the （）

A、crankcase

B、cylinder head

C、valve cover

D、engine frame

As its temperature rises, the volume of fuel oil in the tanks will （）.

A、remain the same

B、increase

C、decrease

D、none of the above

I find （）

A、it difficult for them to finish the job in time

B、difficult for them to finish the job in time

C、they have much difficulty to finish the job in time

D、that difficult for them to finish the job in time

The design of for a flash type evaporator is of critical importance because it must provide an optimum feedwater spray pattern that facilitates the flashing process, and it must also maintain a pressure differential between successive stages（）

A、condenser

B、flashing device

C、lashing device

D、vacuum pump

Valve cages are used on some large diesel engines to （）

A、reduce wear on the valve stem

B、permit the use of alloy valve seat materials

C、reduce heat transfer from the valve seat

D、facilitate valve removal for servicing