单项选择题
A.used only for pollution response
B.owned and operated by the US government
C.used only within a barge fleeting area
D.used only on inland waters
单项选择题 Fire protection and manning regulations for towing vessels state that the Master or person in charge must ensure that all crew members who have not participated in the drills or received the safety orientation（）.
单项选择题 Fire may be spread by which means?（）
单项选择题 Fire in an engine compartment is best extinguished with carbon dioxide gas (CO2) and by（）.