单项选择题
A.will be coming to periscope depth
B.will be coming to the surface
C.is on the bottom in distress
D.is in distress and will try to surface
单项选择题 A vessel，which does not normally engage in towing operations，is towing a vessel in distress.She（）.
单项选择题 A vessel sounding a fog signal of one short，one prolonged，and one short blast is indicating that the vessel is（）.
单项选择题 A vessel showing a yellow light over a white light at night is a vessel（）.