In a pneumatic automation system, a unit producing a signal to govern the position of the controller of the measured variable, relative to the value of the measured variable, is said to have（）.
1、Dirt in a fuel oil system of a diesel
Dirt in a fuel oil system of a diesel engine can cause （）Adamage to strainersBover-speeding of the engineCexcessive cooling of the engineDinjector damage
2、In a central cooling system, used in s
In a central cooling system, used in some modem ships, sea water is supplied to cool （）which will circulate to other individual cooler, greatly reducing the corrosion problems.Afresh waterBsea waterCcooling oilDemulsio
3、In a tree directory of a file system,
In a tree directory of a file system, relative path name can be used to find files for improving directory retrieval.To do this, which directory of the followings should be set up?Aparent directoryBchild directoryCworking directoryDhome directory
4、In the refrigeration system, a shortag
In the refrigeration system, a shortage of refrigerant is indicated by （）.Athe compressor short cycling on high pressure cut out switchBhigh suction pressureChigh head pressureDbubbles in the sight gla
5、In a central cooling system, used in s
In a central cooling system, used in some modem ships, sea water is supplied to cool （）which will circulate to other individual cooler, greatly reducing the corrosion problems.Amain bearingsBsea waterCcooling oilDlower temperature fresh water
6、In a refrigeration system, the refrige
In a refrigeration system, the refrigerant absorbs the latent heat of vaporization in the（）.AcompressorBcondenserCreceiverDevaporator