单项选择题
A.A triangular flag above or below a ball
B.The International Code Signal of distress indicated by "JV"
C.A green smoke signal
D.Flames on the vessel as from a burning tar barrel
单项选择题 Which EPIRB transmits a distress alert that is received and relayed by an INMARSAT satellite?（）
单项选择题 Which condition represents the appropriate time for setting off distress flares and rockets? （）
单项选择题 Which condition represents the appropriate time for setting off distress flares and rockets? （）