单项选择题
A.steel
B.aluminum in an aluminum-hulled vessel
C.schedule 80 fire resistant plastic pipe
D.nickel-copper，copper-nickel or annealed copper
单项选择题 Fire protection regulations apply to those towing vessels（）.
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?（）