It should be noted（）the use of synthetic mooring ropes able to produce sparks by their manipulation is absolutely forbidden on board petroleum tankers and LPG or LNG carriers，or any vessels carrying inflammable substances.

A.Make periodic inspections of bilges
B.Keep the barge under constant surveillance
C.Have a properly certificated tankerman or at least one licensed officer on board the towing vessel
D.Verify ullage readings

A.above the floor plates of the bilges
B.above the carburetor level
C.at the lowest point of the bilge areas
D.at no particular level

A.to the top to expel all vapors from the tanks
B.to the top so the operator is certain how much fuel he has aboard
C.with only sufficient fuel for the planned trip so excess gasoline is not carried
D.to near the top with some space allowed for gasoline expansion