单项选择题
Which of the following shall not the officers in charge of the navigational watch do?（）
A.continue to be responsible for the safe navigation of the ship B.Leave the bridge C.Keep the watch on the bridge D.Use any available navigational aids necessary to ensure that the ship follows the planned course
单项选择题 The helm command PORT TWENTY means（）.
单项选择题 The circulation around a low pressure center in the Northern Hemisphere is（）.
单项选择题 How long are you prohibited to consume alcohol prior to serving as a member of a watch?（）
