Stop wasting our precious water

　　Stop wasting our precious water

　　世界不仅饥饿，而且缺水。你可能会觉得奇怪，因为近75%的地球表面被水覆盖。但是大约97%的数量庞大的海水，或盐水。人只能喝，用其他3%——来自河流，湖泊，地下淡水，和其他来源。我们甚至不能使用，因为它的一部分是在冰山和冰川的形成。更糟糕的是，其中一些已经被污染了。

　　然而，今天的情况，少量的新鲜水，这是不断的被降雨，对我们来说还是足够。但我们对水的需求增长迅速——几乎一天一天。如果我们采取措施来处理这个问题，现在我们可以避免严重的全球水资源短缺。限量供水会对农业和工业产生坏的影响。让我给你一个小的对流换热的水是必要的产业。你知道，生产一吨的钢，它需要大约91，000公升的水?

　　我们必须学会如何停止浪费我们宝贵的水。我们应该采取的第一步就是要发展水再利用的方法。该领域的实验已在进行，但只有在一个小规模。我们的系统，和宇宙飞船一样重要。

　　【正文】：

　　The world is not only hungry,but also thirsty for water. This may seem strange to you, since nearly 75 % of the earth's 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.