A.cofferdamsB.empty cargo spacesC.gas tight bulkheadsD.……

单项选择题Regulations require that tank vessels handling grade B liquids shall have their cargo pumps separated from all sources of vapor ignition by（）.

A.cofferdams
B.empty cargo spaces
C.gas tight bulkheads
D.areas equipped with power ventilation

单项选择题Regulations require that pumprooms on tank vessels carrying grade C liquid cargo with machinery spaces below the freeboard deck be ventilated with（）.

A.power ventilation
B.gooseneck vents and flame screens
C.at least two ducts extending to the weather deck
D.a vent header system

单项选择题Regulations require that cargo tanks carrying grades D or E liquids on tank barges be vented with（）.

A.gooseneck vents and flame screens
B.pressure-vacuum relief valves
C.branch vent lines and a vent header
D.forced draft blowers

单项选择题Regulations require that cargo pumps in tankers carrying grade D liquid cargo shall be isolatedfrom sources of vapor ignition by（）.

A.cofferdams
B.gastight bulkheads
C.passageways or living quarters
D.general cargo spaces

单项选择题Regulations require that cargo pumprooms on tank barges (constructed in 1965) carrying grades B or C liquid cargoes have power ventilation systems which can completely change the air in （）.

A.1 minute
B.3 minutes
C.5 minutes
D.10 minutes