89 Water Power The Greatest Force on Earth

CHAPTER 1 Water on Earth IT IS NO SURPRISE WE CALL THE EARTH "THE BLUE PLANET." AFTER ALL, OVER 60 PERCENT OF ITS SURFACE IS COVERED WITH WATER. It is water that gives Earth its beautiful blue color that we see in photographs taken from space. No other planet that we know of in the universe has so much water, that amazing element so essential to life. Water goes through a cycle that never ends. It falls from the sky as rain and snow, sleet, and hail. On high mountains, glaciers melt and water flows from narrow streams and wide rivers into lakes and eventually into the seas and oceans. Then, through a process called evaporation, water rises from the seas to the skies where it turns into clouds. And the cycle begins again. Water can be liquid, solid, or gas; it can be gentle or rough; it can bring life or death.

第一章地球上的水我们称地球为“蓝色星球”并不奇怪。 毕竟，超过60%的火星表面被水覆盖。 我们在太空拍摄的照片中看到，是水赋予了地球美丽的蓝色。 据我们所知，宇宙中没有其他星球有如此多的水，这种神奇的元素对生命至关重要。 水的循环永无止境。 它以雨雪、雨夹雪和冰雹的形式从天而降。 在高山上，冰川融化，水从狭窄的溪流和宽阔的河流流入湖泊，最终流入海洋。 然后，通过一个被称为蒸发的过程，水从海洋上升到天空，在那里变成云。 这样的循环又开始了。 水可以是液体、固体或气体；它可以是温和的，也可以是粗糙的；它可以带来生死。

Water has power over us maybe more than anything else on the planet! Without water, no human, animal, or plant could survive. Humans have long used water for washing, growing food, and raising animals. Water has also been used as a means of transportation, as a source of recreation, and as a household tool. Now, we also use water as an industrial tool and as a source of energy. But too much water can be a bad and dangerous thing. Think of floods, for example. Fast-moving, deep water can drown people; it can sweep away vehicles and even buildings. Also, floodwater may contain bacteria that cause diseases and that can affect our drinking water. Water gives us power, but it also has power over us.

水对我们的影响可能比地球上任何东西都大！没有水，人类、动物和植物都无法生存。 长期以来，人类一直用水来洗涤、种植食物和饲养动物。 水也被用作交通工具、娱乐来源和家庭工具。 现在，我们也把水作为一种工业工具和能源。 但过多的水可能是一件糟糕而危险的事情。 以洪水为例。 湍急的深水会把人淹死；它可以横扫车辆甚至建筑物。 此外，洪水中可能含有导致疾病的细菌，这可能会影响我们的饮用水。 水给我们力量，但它也有控制我们的力量。

CHAPTER 2 Water in Industry THE AMOUNT OF WATER USED IN INDUSTRY IS GROWING STEADILY EACH YEAR. AS MORE COUNTRIES DEVELOP ECONOMICALLY, MORE WATER WILL BE NEEDED FOR INDUSTRIAL USE. Water is important in industry. In fact, about 20 percent of all the water we use around the world is for industrial purposes. We need water in every step of the industrial process. For example, sometimes water is needed in the production of food items like soft drinks, soups, and juices. And we also need it for things like soap, shampoo, paint, and cleaning liquids. But did you know that water is required for the production of plastic and glass? Water is even used when making cars! It takes about 2,000 liters of water to make one car tire! It sounds unbelievable, but it's true.

第二章工业用水工业用水量每年都在稳步增长。 随着越来越多的国家发展经济，工业用水将需要更多的水。 水对工业很重要。 事实上，世界上大约20%的水是用于工业用途的。 我们在工业生产的每一步都需要水。 例如，有时在生产软饮料、汤和果汁等食品时需要水。 我们也需要它来制造肥皂、洗发水、油漆和清洁剂。 但是你知道生产塑料和玻璃需要水吗？ 水甚至被用于制造汽车！制造一个汽车轮胎需要大约2000升水！这听起来难以置信，但却是真的。

We need tools to make things, and water can also be used as a tool. For example, water is often used to cut things. When a line or jet of water is shot out at a high speed and under high pressure, it can be very strong— strong enough to cut through glass, metal, and stone. Because of this, water jet cutting machines are used in industries like mining and aerospace to cut things to the right shape. Water jets are also used at the dentist's office to help us keep our teeth clean. Fortunately, they're not as strong as the ones used to cut stone or metal! Water is also used in industry as a lubricant something that can help prevent machines from wearing out when their parts move against each other. Right now, most industrial lubricants are made with oil, but because using oil in this way is not good for the environment, inventors are developing water-based lubricants. Because water is inexpensive and easy to get, it is also used as a coolant— to cool down the moving parts of machines in factories and power plants.

我们需要工具来制造东西，水也可以被用作工具。 例如，水经常被用来切割东西。 当一条线或一束水在高速和高压下射出时，它可以非常强大——强大到足以切割玻璃、金属和石头。 正因为如此，水射流切割机被用于采矿和航空航天等行业，以切割出正确的形状。 牙医办公室也使用喷水器来帮助我们保持牙齿清洁。 幸运的是，它们不像用来切割石头或金属的那样坚固！在工业中，水也被用作润滑剂，当机器的部件相互碰撞时，水可以帮助防止机器磨损。 目前，大多数工业润滑剂都是用石油制成的，但由于以这种方式使用石油对环境不利，发明家们正在开发水基润滑剂。 因为水既便宜又容易获得，所以它也被用作冷却剂——冷却工厂和发电厂中机器的运动部件。

Water is also used to move things where they need to go. Trees are cut down and floated along rivers from faraway forests, for example. It would be hard, in fact, for trade to exist without water as a means of transportation. Shipping is a huge industry that helps us move the things we make around the world as cheaply as possible. And water is also used to transport waste— including human waste! —to waste-treatment facilities, where it is diluted, broken down, and dealt with safely.

水也被用来移动它们需要去的地方。 例如，树木从遥远的森林里被砍倒，漂浮在河流上。 事实上，如果没有水作为运输工具，贸易就很难存在。 航运是一个巨大的行业，它帮助我们以尽可能低的成本将我们制造的东西运往世界各地。 水也被用来运输废物——包括人类的废物！到废物处理设施，在那里它被稀释、分解和安全处理。

Water is also used to create the power we need to keep our industries running. Hydroelectric generating plants use the energy of falling water to turn turbines, which then create electricity. This electricity is taken to cities and towns along power lines. Without water, most industrial work would be more dangerous, more expensive, and, in some cases, impossible. But there are problems. For example, industrial processes may cause pollution. Dangerous chemicals can pollute the water, harm people, and damage the environment.

水也被用来制造维持工业运转所需的电力。 水力发电厂利用落水的能量转动涡轮机，从而发电。 这些电力通过电线输送到城镇。 没有水，大多数工业工作将更加危险，更加昂贵，在某些情况下，甚至不可能。 但也存在一些问题。例如，工业生产过程可能造成污染。 危险化学品会污染水源，危害人类，破坏环境。