单项选择题
A.sea state
B.names of witnesses
C.time of its occurrence
D.wind direction and velocity
单项选择题 If you hear the firing of a gun at one minute intervals from another vessel，this indicates that（）.
单项选择题 If you are transmitting a distress message by radiotelephone you should（）.
单项选择题 If you are on the beach and are signaling to a small boat in distress that your present location is dangerous and they should land to the left，you would（）.