新东方背诵文选 L44.Obtaining Fresh water from icebergs
时间：2018-12-15 作者：英语课 分类：新东方背诵文选
英语课
The concept of obtaining fresh water from icebergs 1 that are towed to populated areas and arid 2 regions of the world was once treated as a joke more appropriate to cartoons than real life. But now it is being considered quite seriously by many nations, especially since scientists have warned that the human race will outgrow 3 its fresh water supply faster than it runs out of food.
Glaciers 4 are a possible source of fresh water that has been overlooked until recently. Three-quarters of the Earth's fresh water supply is still tied up in glacial ice, a reservoir of untapped fresh water so immense that it could sustain all the rivers of the world for 1,000 years. Floating on the oceans every year are 7,659 trillion metric tons of ice encased in 10000 icebergs that break away from the polar ice caps, more than ninety percent of them from Antarctica.
Huge glaciers that stretch over the shallow continental 5 shelf give birth to icebergs throughout the year. Icebergs are not like sea ice, which is formed when the sea itself freezes, rather, they are formed entirely 6 on land, breaking off when glaciers spread over the sea. As they drift away from the polar region, icebergs sometimes move mysteriously in a direction opposite to the wind, pulled by subsurface currents. Because they melt more slowly than smaller pieces of ice, icebergs have been known to drift as far north as 35 degrees south of the equator in the Atlantic Ocean. To corral them and steer 7 them to parts of the world where they are needed would not be too difficult.
The difficulty arises in other technical matters, such as the prevention of rapid melting in warmer climates and the funneling 8 of fresh water to shore in great volume. But even if the icebergs lost half of their volume in towing, the water they could provide would be far cheaper than that produced by desalinization, or removing salt from water.
1 icebergs
n.冰山，流冰( iceberg的名词复数 )
- The drift of the icebergs in the sea endangers the ships. 海上冰山的漂流危及船只的安全。 来自《简明英汉词典》
- The icebergs towered above them. 冰山高耸于他们上方。 来自辞典例句
2 arid
adj.干旱的；(土地)贫瘠的
- These trees will shield off arid winds and protect the fields.这些树能挡住旱风,保护农田。
- There are serious problems of land degradation in some arid zones.在一些干旱地带存在严重的土地退化问题。
3 outgrow
vt.长大得使…不再适用；成长得不再要
- The little girl will outgrow her fear of pet animals.小女孩慢慢长大后就不会在怕宠物了。
- Children who walk in their sleep usually outgrow the habit.梦游的孩子通常在长大后这个习惯自然消失。
4 glaciers
冰河，冰川( glacier的名词复数 )
- Glaciers gouged out valleys from the hills. 冰川把丘陵地带冲出一条条山谷。
- It has ice and snow glaciers, rainforests and beautiful mountains. 既有冰川，又有雨林和秀丽的山峰。 来自英语晨读30分（高一）
5 continental
adj.大陆的，大陆性的，欧洲大陆的
- A continental climate is different from an insular one.大陆性气候不同于岛屿气候。
- The most ancient parts of the continental crust are 4000 million years old.大陆地壳最古老的部分有40亿年历史。
6 entirely
ad.全部地，完整地；完全地，彻底地
- The fire was entirely caused by their neglect of duty. 那场火灾完全是由于他们失职而引起的。
- His life was entirely given up to the educational work. 他的一生统统献给了教育工作。