单项选择题
A.the surface of the sea
B.high waters and low waters
C.all low waters
D.the lower of the two daily low tides
单项选择题 In the Sargasso Sea there are large quantities of seaweed and no well defined currents. This area is located in the（）.
单项选择题 In the Northern Hemisphere you are caught in the dangerous semicircle of a storm with plenty of sea room available. The best course of action is to bring the wind on the（）.
单项选择题 In polar regions you should NOT expect to see（）.