如题所述
第1个回答 2011-08-23
Our water poloSomeone says, our earth should be called water polo. This makes some sense, because we live in this planet with water, and 71% of the surface area occupied by water. The astronaut, the earth is a blue ball, very bright, the sun family of the one and only. The earth's water is very great, a total volume of 1386000000 cubic km. Among them, 96.5% in the ocean; 1.76% in glaciers, permafrost, snow cover, is a solid state; 1.7% in the ground; the remaining, lakes, rivers, dispersed in the atmosphere and organisms. So we can say, from heaven to earth, from land to ocean, water everywhere in the world.Shaking heaven and earth 's water cycle, all the water in the world is a linked system. Sea water in the sunlight irradiation, continuous evaporation, water vapor to diffuse in the ocean; a portion of the vapor is airflow to freeze over land, it condenses into small droplets, into the cloud, and falls to the ground is rain or snow; snow water landing, some flow into the pit, or into the ground, some into the minor groove, sinks into the river, to the sea. Numerous small water drops is kept in the world tourism. Water cycle to ensure human fresh water supply. Know the circulation of water, and you can explain: cloud's hometown in where? Why is a river in day and night is always the stream never stops flowing.? Why thousands of years, so many rivers flow into the ocean, but the ocean not overflow?Fresh water where the water on the earth, although large quantities, and can directly use it in production and life, and has a small. First of all, sea salt and bitter, not drinking, not pouring in, it will be difficult for the industry. Secondly, freshwater total consumption 2.6% the left and right sides, most of them ( 99%), frozen in away from human two north-south and permafrost, cannot use, less than 1% of fresh water, they are scattered in the lakes, rivers and under the ground. And the whole world total water volume as a drop in the bucket compared, fresh water追问
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