单项选择题
A.Effect of the moon's gravity
B.Fetch
C.Wind velocity
D.Length of time a wind has been blowing
单项选择题 In a tropical cyclone，in the Northern Hemisphere，a vessel hove to with the wind shifting counterclockwise is（）.
单项选择题 Cold water flowing southward through the western part of the Bering Strait between Alaska and Siberia is joined by water circulating counterclockwise in the Bering Sea to form the（）.
单项选择题 Advection fog is most commonly caused by（）.