A.a blast of from five to seven seconds' duration B.a blast of from five to six seconds' duration C.a blast of from four to six seconds' duration D.a blast of from six to seven seconds' duration
单项选择题The ship will be()demurrage soon.
A.at B.for C.in D.on
单项选择题The ship is now down()head.
A.on B.by C.in D.for
单项选择题The ship is not very stable,please()when making a turn.
A.stop down B.speed down C.slow down D.down slow
单项选择题The radiotelegraphy safety messages for condition indicating distress,urgency and safety,respectively,are().
A.SOS,ZZZ,XXX B.SOS,UUU,SSS C.SOS,XXX,TTT D.SOS,TTT,UUU
单项选择题The most likely time for oil pollution while bunkering is when().
A.final topping off is occurring B.first starting to receive fuel C.hoses are being blown down D.hoses are disconnected and being capped