单项选择题
A.must be from dead ahead B.speed must be zero C.must be from dead astern D.must be on the beam
The apparent wind can be zero when the true wind is fro...
单项选择题The apparent wind can be zero when the true wind is from（）.
A.ahead and equal to the ship's speed B.astern and equal to the ship's speed C.ahead and equal to twice the ship's speed D.astern and equal to twice the ship's speed
Steam fog is most likely to occur on the Mississippi an...
单项选择题Steam fog is most likely to occur on the Mississippi and Ohio Rivers in（）.
A.spring，around late evening B.spring，around early evening C.fall，around early morning D.fall，around midday
Radiation fog（）.A.always forms over waterB.is formed by...
单项选择题Radiation fog（）.
A.always forms over water B.is formed by a temperature inversion C.is thinnest at the surface D.dissipates during the evening
