The velocity of the wind，its steady direction，and the amount of time it has blown determines a wind driven current’s（）.

The velocity of the current in large coastal harbors is（）.

A.predicted in Tidal Current Tables
B.unpredictable
C.generally constant
D.generally too weak to be of concern

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The velocity of a rotary tidal current will be decreased when the Moon is（）.

A.at apogee
B.new
C.full
D.All of the above

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