大学英语：In most of the oceans and seas some

　　3.In most of the oceans and seas some of the water is found to be flowing in a particular direction - that is to say， from one part towards another part of the ocean or sea concerned.

　　to be flowing不定式作主语补语

　　concerned 是分词作定语，修饰the ocean or sea

　　4.There are many thousands of currents in the waters of the oceans and seas ，but only certain of the stronger and better marked currents are specially named and of great importance.

　　Thousands/hundreds of + 名词复数

　　Eg.Hundreds of meters

　　此处waters指的是“大片的水，水域”

　　peoples 表示人种

　　woods 表示森林，树木