/ˈəʊʃn ||; ˈoʃən/noun1 [U] (especially US 尤为美) the mass of salt water that covers most of the surface of the earth 海洋;大海: Two thirds of the earth's surface is covered by ocean. 地球表面有三分之二被海洋覆盖。
2 [C] (also Ocean) one of the five main areas into which the water is divided 洋(地球上的五大洋之一): the Atlantic/Indian/Pacific Ocean 大西洋;印度洋;太平洋 ☞Look at sea. 参看sea。 ☞picture at current 见current插图
a drop in the ocean→
DROP²