单项选择题
A.fire a green star to the left
B.send the letter K by light and point to the left
C.place an orange signal to your left as you signal with a white light
D.send the code signal S followed by L
单项选择题 If more than one raft is manned after the vessel has sunk，you should（）.
单项选择题 If an airplane circles a vessel 3 times，crosses the vessel’s course close ahead while rocking the wings，and heads off in a certain direction，what does this indicate（）.
单项选择题 HM Coastguard is primarily（）for the initiation and co-ordination of civil maritime SAR operations in the UK.