As he walked out the court, he was ______ with frustration and rage.

A．it is in position in the middle of the tunnel
B．it can move on a monorail suspended from the roof of the tunnel
C．it runs on a monorail and can take quick action
D．its modified water main can run along the tunnel quickly

A．a prototype has not yet been accepted
B．financial backing is not available
C．the machine will need fire-resistant sensors
D．the machine would not work if the ventilation was overwhelmed