With the development of industrialization, fresh water has been scarce in many places in the world. It is reported that 75% of the rivers and lakes on the earth have been polluted, which means that more and more people are in danger of living without water, which will obviously lead to the disappearance of human being. So, it is time to treasure the fresh water. The best way to save water is to make the best of every drop of water before disposing of it. So it is time to take action now!