单项选择题
A.the gun is being used to sound passing signals
B.the vessel is in distress
C.all vessels are to clear the area
D.all is clear and it is safe to pass
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（）.
单项选择题 If we had stayed at that port much longer，we（）the tropical storm.