单项选择题
A.open and individual tank valves open
B.open and the individual tank valves closed
C.closed and the individual tank valves closed
D.closed and the individual tank valves open
单项选择题 If you are fighting a fire below the main deck of your vessel，which action is most importantconcerning the stability of the vessel? （）
单项选择题 If a leak occurred while loading diethylenetriamine，the chemical data guide indicates you would smell an odor similar to（）.
单项选择题 Hoses used for cargo transfer operations must be tested and inspected at specified intervals by（）.