单项选择题
A.occasionally B.accidentally C.often D.usually
We（）a sharp lookout while sailing in the iced waters.A....
单项选择题We（）a sharp lookout while sailing in the iced waters.
A.keep B.kept C.are keeping D.have kept
When a mis-entry（）in the logbook, a red line would be d...
单项选择题When a mis-entry（）in the logbook, a red line would be drawn through that part.
A.has made B.make C.has been made D.is making
（）, which consisted of seven short blasts and one prolo...
单项选择题（）, which consisted of seven short blasts and one prolonged blast, all passengers have to go to their assembly station.
A.When the distress alert is sounded B.When the emergency equipment is switching on C.When the general emergency alarm is sounded D.When the distress broadcast is sounded
