全球淡水资源短缺(Global Shortage of Fresh Water)
there is fresh water in rain, in rivers and wells. this fact leads us to think that fresh water is everywhere and it will never be used up in the world. but the fact is that such a belief is unfortunately wrong and possibly dangerous.
we know that despite the fact that seventy percent of the earth's surface is covered with water, only a little part of it is fresh water. yet the demand for fresh water in our daily life and in industry seems great. moreover, with the expansion of the population and development of industry, the amount of the fresh water needed will increase even rapidly. it is estimated that if such a trend continues, the fresh water on earth will be exhausted very soon. what is worse, more and more water resources are being polluted, making the water unfit to use.
we still have time if we begin to act right now. we must warn the people of the importance of fresh water and the danger we are facing. we should control the wastes produced by factories. we should also develop new ways to use our limited fresh water more economically and recycle the used water. in short, the global shortage of fresh water can be solved if some measures are taken right away.