The SongHua river has been polluted last week. The government has stopped the tap water, so the people in Harbin get some trouble about drinking the water. It is a difficult problem, because nobody can live well without the water. So the government tries its best to find the way to solve the problem.
At the same time, many cities give help to Harbin, hundreds of trucks transport the water to Harbin. Everybody needs others help when they get trouble. Like people, like city. Our country likes a big family; the city is the member of the family. Like the family, helping each other is responsibility of every member.
The world is not only hungry,but also thirsty for water. This may seem strange to you, since nearly 75 % of the earths surface is covered with water. But about 97% of this huge amount is sea water, or salt water. Man can only drink and use the other 3% -- the fresh water that comes from rivers, lakes,underground, and other sources. And we cannot even use all of that, because some of it is in the form of icebergs and glaciers. Even worse, some of it has been polluted.
However, as things stand today, this small amount of fresh water, which is constantly being replaced by rainfall, is still enough for us. But our need for water is increasing rapidly-- almost day by day. Only if we take steps to deal with this problem now can we avoid a severe worldwide water shortage later on. A limited water supply would have a bad effect on agriculture and industry. Let me give you just one small exampie of how necessary water is to industry. Did you know that to produce a single ton of steel, it takes about 91, 000 liters of water?
We all have to learn how to stop wasting our precious water. One of the first steps we should take is to develop ways of reusing it. Experiments have already been done in this field, but only on a small scale. For us, the systems are as important as the spacecraft.
Water is essential to living things. For instance, if there is no enough water in a human body, a person may feel uncomfortable or get sick easily. To make matters worse, one may die of thirst. Similarly, plants may wither or die for lack of water. It is apparent that all living things need water to keep alive.
Judging from the importance of water, we should know how to conserve water. The first thing is to stop polluting water because what we really need is clean water. At the same time, be sure to turn off the faucet immediately after using water. And we should make efficient use of water to avoid wasting it. One way is to recycle as much water as possible. To sum up, we should economize on water so as to maintain the abundance of water, which is an indispensable element of life.
