单项选择题
A.Aye Aye Sir B.Right 15 degrees rudder C.Rudder is right 15 degrees D.No reply is necessary，just carry out the order
A heavy，thick-walled tube，usually steel，used between th...
单项选择题A heavy，thick-walled tube，usually steel，used between the drill pipe and the bit in the drill stem to weight the bit in order to improve its performance is called a（）.
A.heavy-walled drill pipe B.tool joint C.down hole tool D.drill collar
A heavy steel curved arch constructed athwartships and ...
单项选择题A heavy steel curved arch constructed athwartships and above the after deck on a towing vessel is sometimes called a（）.
A.main brace B.tow span C.jockey bar D.None of the above
A head-on situation at night is one in which you see de...
单项选择题A head-on situation at night is one in which you see dead ahead a vessel showing（）.
A.one sidelight B.one sidelight and a masthead light C.one sidelight and two masthead lights D.both sidelights of a vessel and her masthead light(s)
