单项选择题
A.opening the automatic drain plugs
B.draining the water pockets
C.using the electric bilge pump
D.using the bailers and cellulose sponge
单项选择题 A vessel in distress should send by radio telephone the two tone alarm signal followed immediately by the（）.
单项选择题 A distress signal（）.
单项选择题 AS SOON AS I HAVE FURTHER INFORMATION I WILL MAKE ANOTHER ANNOUNCEMENT. I ASK YOU KINDLY TO REMAIN CALM. THERE IS NO DANGER AT THIS TIME. These words are likely from（）.