单项选择题
A.The shaft B.The mechanical C.The electric D.The indicated
The operating medium for control systems may be （）.A.co...
单项选择题The operating medium for control systems may be （）.
A.compressed air B.hydraulic oil C.electricity D.All of the above
（） systems are provided with a stand-by device which wi...
单项选择题（） 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
The difference between measured and desired values is c...
单项选择题The difference between measured and desired values is called （）.
A.make-up B.desired value C.deviation D.set value
