单项选择题
A.International Code Signal "AA"
B.orange-colored smoke
C.red flares
D.the repeated raising and lowering of outstretched arms
单项选择题 According to the “Vessel Bridge-to-Bridge Radiotelephone Act”，your radiotelephone log must contain（）.
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（）.