單項選擇題

The operating medium for control systems may be （）.

A.compressed air
B.hydraulic oil
C.electricity
D.All of the above

你可能感興趣的試題

單項選擇題

（） systems are provided with a stand-by device which will automatically be put in use in the even of the running device failing through a fault condition.

A.Alarm
B.Monitoring
C.Auto start-up
D.None of the above

單項選擇題

The difference between measured and desired values is called （）.

A.make-up
B.desired value
C.deviation
D.set value