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水大约占地球表面积的四分之三,但水资源短缺问题却一直困扰着我们。你知道为什么吗?The world is not hungry,but it is thirsty.About 97% of water on the earth is sea water.We can’t drink it.We can’t use it for watering(给……浇水)plants.Man can only drink and use the fresh water that comes from rivers and lakes.
Water accounts for about three-quarters of the Earth’s surface area, but the problem of water shortages has plagued us. Do you know why? The world is not hungry, but it is thirsty. About 97% of water on the earth is sea water. We can not drink it.We can not use it for watering plants.Man can only drink and use the fresh water that comes from rivers and lakes.