Dangerous goods required to be “carried on deck only” should not be carried on closed vehicle decks，but may be carried on open vehicle deck when authorized by the competent authority concerned. （）

A.combustible liquid
B.flammable liquid
C.flammable solid
D.poison B

A.Skull and crossbones
B.Yellow
C.Red
D.White

A.the method for the proper stowage of a dangerous cargo
B.the necessity of lashing，securing and piling of awkward or lengthy cargo
C.whether different goods can be stowed together in one hold
D.ventilation method for hydrous cargo