单项选择题
In which month will the equatorial counter current be strongest? （）
A.January B.April C.August D.October
单项选择题 In mid-ocean，the characteristics of a wave are determined by three factors. What is NOT one of these factors?（）
单项选择题 Generally speaking，a ship steaming across the North Pacific from Japan to Seattle is likely to experience（）.
单项选择题 Currents are（）in rate and direction.
