单项选择题
A.stopper B.screen C.filter D.restrictor
A decrease in barometric pressure is associated with al...
单项选择题A decrease in barometric pressure is associated with all of the following except（）.
A.rising warm air B.proximity to a low pressure area C.inward spiraling circulation D.clear dry weather
（）during the voyage any case or suspected case of plagu...
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
（）day，pilot flag should be displayed from main mast.A.F...
单项选择题（）day，pilot flag should be displayed from main mast.
A.From B.By C.on D.With
