Water is an important substance on the earth that cannot be replicated or replaced. With water, there are all kinds of life. The total water reserves on the earth are about 1.4 billion cubic kilometers, which is a very amazing data. 1.4 billion cubic kilometers, think about it, two-thirds of the entire earth is sea! Although there are so many water resources on the earth, only 2.5% of the freshwater resources that can be used for human life and production, that is, there are about 560 million cubic kilometers. Although this data is also very large, think about it again, there are so many people on the earth, especially in our country, with a population of 1.3 billion, the per capita water resources in our country are only one-fourth of the world's per capita level, and nearly two-thirds of cities have varying degrees of water shortage.
