单项选择题
（）during the voyage any case or suspected case of plague，cholera，yellow fever，smallpox，typhus or relapsing fever?
A.Has there been B.Have there been C.Has there D.Have there
单项选择题 （）day，pilot flag should be displayed from main mast.
单项选择题 （）any sick person on board now apart from the above-mentioned cases?
单项选择题 （）any person died on board during the voyage otherwise than as a result of accident?
