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人类赖以生存的地球,表面有四分之三的面积覆盖着海洋.在那四分之一的陆地上,河流湖泊星罗棋布,森林草原比比皆
On the surface of the earth, three-fourths of the surface of the Earth upon which mankind depends, is covered by oceans, on which rivers and lakes are dotted with forests and grasslands abound