单项选择题

When stand-by engine instructions have been received, it’s necessary to make it sure that all valves in the various systems are（）

A.operational
B.open
C.closed securely
D.at middle position

<上一题目录下一题>

热门试题

单项选择题

The monitoring function may serve all of the following purposes except（）

A.instigating corrective action
B.indicating values of controlled variables
C.warning of off-limit conditions
D.providing record of performance

单项选择题

A feedback is an input（）

A.which governs the state of a variable
B.which provides a visual and audible alarm
C.which indicates values of controlled variables
D.which measures the state of the controlled variable