单项选择题
The officer of the watch should（）comply with the collision rules.
A.some times B.often C.at all times D.seldom
单项选择题 The phrase when built in the certificate of vessel’s nationality definitely means（）.
单项选择题 The port in which crew or passengers go on board the ship is called（）.
单项选择题 The principal purpose of adjustment of the magnetic compass is to eliminate（）as far as possible.
