单项选择题
A.danger B.dangered C.dangeroused D.dangerous
A long blast to warn the vessels（）vicinity.A.inB.onC.at...
单项选择题A long blast to warn the vessels（）vicinity.
A.in B.on C.at D.for
CO2 cylinder weighed（）normal weight.A.light thanB.light...
单项选择题CO2 cylinder weighed（）normal weight.
A.light than B.lighter C.light D.lighter than
Vessel（）still to bunker 50 tones of fresh water.A.haveB...
单项选择题Vessel（）still to bunker 50 tones of fresh water.
A.have B.have been C.has been D.has
