单项选择题
A.two balls in a vertical line B.a diamond shape where it can best be seen C.a ball on each end of the tow D.no dayshape
A tug is towing three manned barges in line in fog. The...
单项选择题A tug is towing three manned barges in line in fog. The first vessel of the tow should sound （）.
A.no fog signal B.one short blast C.one prolonged and three short blasts D.one prolonged，one short，and one prolonged blast
A triangular daymark would be colored（）.A.redB.red and ...
单项选择题A triangular daymark would be colored（）.
A.red B.red and white C.green D.green and white
A towing vessel 30 meters in length is pushing barges a...
单项选择题A towing vessel 30 meters in length is pushing barges ahead. How many white masthead lights is the vessel REQUIRED to show at night?（）
A.One B.Two C.Three D.Four
