单项选择题
A.live B.dead C.excited D.on line
（） control system is one in which the control action is...
单项选择题（） control system is one in which the control action is independent of the output.
A.Feed back B.Negative feed back C.Close loop D.Open loop
（） power is the power developed within the cylinder and...
单项选择题（） power is the power developed within the cylinder and can be measured by an engine indicator.
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
