单项选择题
To make sure of getting the full advantage of a favorable current，you should reach an entrance or strait at what time in relation to the predicted time of the favorable current?（）
A.One hour after the predicted time B.At the predicted time C.30 minutes before flood，one hour after an ebb D.30 minutes before the predicted time
单项选择题 Tide is（）in direction ENE.
单项选择题 The winds with the greatest effect on the set，drift，and depth of the equatorial currents are the（）.
单项选择题 The velocity of the wind，its steady direction，and the amount of time it has blown determines a wind driven current’s（）.
