单项选择题
The term flood current refers to that time when the water（）.
A.is flowing towards the land B.is moving towards the ocean C.level is not changing D.level is rising because of heavy rains
单项选择题 The steady current circling the globe at about 60°S is the（）.
单项选择题 The speed of an ocean current is dependent on（）.
单项选择题 The set of the ocean current is caused by（）.
