单项选择题
A.at right angles to the flow of the current
B.against the flow of the current
C.in the same direction as the flow of the current
D.over slack water
单项选择题 The horse latitudes are characterized by（）.
单项选择题 The height of a wave is the vertical distance（）.
单项选择题 The edge of a hurricane has overtaken your vessel in the Gulf of Mexico，and the northwest wind of a few hours ago has shifted to the west. This is an indication that you are located in the（）.