英语写作材料

In today's world is faced with a population of three major issues of resources and the environment, in which a variety of water resources is an important irreplaceable resources, water resources has become an important world issues. About 70% of the Earth's surface over an area of water covered the remaining approximately 30% of the surface of the Earth's land has water, but only 2.53% of the water is fresh water for human use. As a result of the development of technical and economic difficulties or limitations, so far, water, deep groundwater, fresh water, such as solid ice and snow was difficult to directly use. Easier development and utilization, and production of human life is most closely related to the lakes, rivers and shallow underground freshwater resources, the total fresh water reserves of only 0.3 4%, less than one ten thousandth of the total global water, so the face of the earth not abundant fresh water resources. With the economic development and populatio