单项选择题
A.immediately above the level of the oil B.at the top of the tank C.in the vent riser D.one meter from the deck
Backfire flame arrestors are installed on（）.A.fuel tank...
单项选择题Backfire flame arrestors are installed on（）.
A.fuel tanks B.spark plugs C.carburetors D.distributors
Automatic fire dampers in ventilation systems are opera...
单项选择题Automatic fire dampers in ventilation systems are operated by use of（）.
A.remotely operated valves B.fusible links C.C02 system pressure switches D.heat or smoke detectors
单项选择题Automatic fire dampers in ventilation systems are operated by a（）.
A.remote operated valve B.fusible link C.CO2 system pressure switch D.heat or smoke detector
