VOA慢速英语2010年-THIS IS AMERICA - White Sands National

ANNOUNCER¹:

Welcome to THIS IS AMERICA IN VOA Special English. I'm Faith Lapidus.

One of the world's great natural wonders is in the state of New Mexico, in the American Southwest. Nature has created huge moving hills of pure white sand. These sand dunes³ cover more than seventy-thousand hectares of desert.

Now, Steve Ember and Mary Tillotson are your guides as we explore White Sands National Monument.

(MUSIC)

VOICE ONE:

White Sands National Monument

It is one of the largest sand dune² fields in the United States. The bright white sand dunes are always changing, always moving, like waves on the ocean. Driven by strong winds, the sand moves and covers everything in its path. It is like a huge sea of sand.

VOICE TWO:

The sand dunes have created an extreme environment. Plants and animals struggle to survive. A few kinds of plants grow quickly to survive burial by the moving sand dunes. Several kinds of small animals have become white in color in order to hide in the sand.

White Sands National Monument protects a large part of this dune field. It also protects the plants and animals that live there. More than five-hundred-thousand people visit White Sands National Monument each year. They climb on the dunes and observe the moving sea of sand.

VOICE ONE:

You may wonder how all this sand arrived in the area. To understand that, you would have to travel back in time two-hundred-fifty-million years. An inland ocean once covered the area. The minerals calcium⁴ and sulfur⁵ were at the bottom of the ocean. Over time, the water slowly disappeared. The calcium and sulfur remained. The minerals formed gypsum rock.

Then, seventy-million years ago, the Earth's surface, or crust⁶, pushed upward⁷. The rocks formed two groups of mountains. Later, the crust pulled apart. The area between the mountains broke and fell down. It formed a half-circle shape of a bowl. This bowl of rock is known as the Tularosa Basin.

VOICE TWO:

About twenty-four-thousand years ago, it rained a great deal in the area. The rain filled the Tularosa Basin and formed Lake Otero. The rain and snow that washed down the mountains into Lake Otero carried gypsum with it.

Gypsum Dunes

Later, Lake Otero almost completely dried up. Gypsum remained. A strong wind moved into the area. It blew across the land for thousands of years. Pieces of gypsum broke off. The wind wore them away to a size small enough to pick up and carry for short distances. Wherever the wind dropped sand, dunes formed.

(MUSIC)

VOICE ONE:

The sand dunes at White Sands National Monument are unusual because they are made of gypsum. Gypsum sand is different from common sand. Most sand is made of quartz⁸, a hard silicon⁹ crystal¹⁰. Gypsum sand is made of softer calcium sulfate. It dissolves easily in water. So it is rarely found in the form of sand dunes. Most gypsum would be carried away by rivers to the sea. But the Tularosa Basin is enclosed¹¹. No rivers flow out of it. So water with dissolved gypsum has nowhere to go.

Gypsum sand is being made all the time. The dunes continue to form and move under the influence of water and wind. Water continues to wash down from the mountains carrying dissolved gypsum into the Tularosa Basin. Wind continues to blow across the Basin carrying the gypsum.

The gypsum sand grains crash into each other. The crash creates tiny lines or scratches on the surface of the sand. These scratches change the way light shines off the surface. This makes the sand appear white. The sand dunes look like great masses of bright white snow. But they are not cold and wet. It only rains about eighteen centimeters each year.

(MUSIC)

VOICE TWO:

There are four kinds of sand dunes at White Sands National Monument. Some of the dunes are small and fast-moving. They are called dome¹² dunes because they are shaped like a half-circle. Few if any plants grow on them. These dunes move the fastest, up to twelve meters a year.

Other dunes are called transverse dunes. They form in long lines across the dune field. They can grow to be one-hundred-twenty meters thick and eighteen meters high.

Another kind of dunes are barchan dunes. They form in areas with strong winds but a limited supply of sand. These dunes have sand in three parts, like a body in the center and two arms on the sides. The sand in the two arms moves faster than the sand in the center.

Parabolic dunes are the opposite of barchan dunes. They form when plants hold sand in the outer parts of the dune but the center of the dune continues to move.

(MUSIC)

VOICE ONE:

You may wonder how anything can live in this extreme environment of a white sand desert. There is not much rain. The heat in summer is intense¹³. The sand lacks nutrients¹⁴.

Yet almost four-hundred kinds of animals live in White Sands National Monument. Many of them are birds or insects. There are also twenty-six kinds of reptiles¹⁵, including rattlesnakes and lizards¹⁶. And there are more than forty kinds of mammals. They include rabbits, foxes and coyotes.

Scientists know that plants and animals often change to be able to live in extreme environments. For example, they change color to protect themselves from enemies. Many of the animals that live in the sand dunes have become white. So it is difficult to see the animals in the sand.

There is another reason why you may not be able to see the animals. Many of them remain underground during the day when it is very hot. They come out at night when it is cooler. You may be able to see their footprints.

VOICE TWO:

Plants do grow in the White Sands dune field. But even plants that grow in most deserts have trouble surviving. A major reason is that the dunes bury any plants in their way as they move across the desert. Yet, a few plants have developed techniques to avoid being buried by moving sand.

For example, some plants grow taller and their roots grow deeper into the sand. The soaptree yucca plant can make its stem¹⁷ grow longer to keep its leaves above the sand. The plant grows up to thirty centimeters a year.

(MUSIC)

VOICE ONE:

White Sands National Monument is about twenty-four kilometers southeast of the city of Alamogordo, New Mexico. In the visitor center at the entrance of the park, you can find out about special activities and guided walks. From the visitor center, you can drive about thirteen kilometers into the center of the dunes. It is like driving on a lonely white planet¹⁸. Along the way there is information that tells about the natural history of the white sands.

You can also explore the dunes on foot. There are four marked trails. Signs along the trail tell about the plants growing in the sand. You can see some unusual and beautiful plants and flowers growing in the sand dunes. But you may not remove or destroy any plants or animals at White Sands.

You can even camp there overnight¹⁹. But you must be careful. It is easy to get lost in the waves of moving sand especially during sandstorms. There is no water to drink. The temperature can rise to thirty-eight degrees Celsius²⁰ in summer. There is no shelter from the sun's rays.

VOICE TWO:

There is another reason to be careful at White Sands National Monument. The White Sands Missile²¹ Range completely surrounds the park. It covers one-million hectares. The missile range was first used as a military weapons testing area after World War Two. It was used to test rockets that were captured²² from the German armed forces. The missile range continues to be an important testing area for experimental²³ weapons and space technology.

These tests take place about two times a week. For safety reasons, both the park and the road from it south to Las Cruces, New Mexico may be closed for an hour or two while tests are taking place.

VOICE ONE:

White Sands National Monument is part of America's National Parks System. The park system includes more than three-hundred-seventy protected areas. White Sands National Monument is just one of the more unusual examples of America's natural and cultural treasures.

(MUSIC)

ANNOUNCER:

Our program was written by Shelley Gollust and read by Steve Ember and Mary Tillotson. I'm Faith Lapidus. Internet users²⁴ can find our programs at voaspecialenglish.com. We hope you join us again next week for THIS IS AMERICA in VOA Special English.

1 announcer   

n.宣布者；电(视)台播音员，报幕员

参考例句：

• The radio announcer said it was nine o'clock.电台播音员报时9点整。
• The announcer tells the listeners what programme comes next.广播员告诉听众下一个是什么节目。

2 dune   

n.(由风吹积而成的)沙丘

参考例句：

• The sand massed to form a dune.沙积集起来成了沙丘。
• Cute Jim sat on the dune eating a prune in June.可爱的吉姆在六月天坐在沙丘上吃着话梅。

3 dunes   

沙丘( dune的名词复数 )

参考例句：

• The boy galloped over the dunes barefoot. 那男孩光着脚在沙丘间飞跑。
• Dragging the fully laden boat across the sand dunes was no mean feat. 将满载货物的船拖过沙丘是一件了不起的事。

4 calcium   

n.钙(化学符号Ca)

参考例句：

• We need calcium to make bones.我们需要钙来壮骨。
• Calcium is found most abundantly in milk.奶含钙最丰富。

5 sulfur   

n.硫，硫磺（=sulphur）

参考例句：

• Sulfur emissions from steel mills become acid rain.炼钢厂排放出的硫形成了酸雨。
• Burning may produce sulfur oxides.燃烧可能会产生硫氧化物。

6 crust   

n.(一片)面包皮，硬外皮，外壳；地壳

参考例句：

• This article focuses on radiation present in the earth crust.本文重点介绍源自地壳的辐射。
• Earth quakes can result from stresses in the earth's crust.地壳内的应力可能引起地震。

7 upward   

adj.向上的，上升的；adv.向上，上升

参考例句：

• The birds flew upward.鸟儿向上飞去。
• Prices have an upward tendency.价格有上升的趋势。

8 quartz   

n.石英

参考例句：

• There is a great deal quartz in those mountains.那些山里蕴藏着大量石英。
• The quartz watch keeps good time.石英表走时准。

9 silicon   

n.硅(旧名矽)

参考例句：

• This company pioneered the use of silicon chip.这家公司开创了使用硅片的方法。
• A chip is a piece of silicon about the size of a postage stamp.芯片就是一枚邮票大小的硅片。

10 crystal   

n.水晶，水晶饰品，结晶体；最好的玻璃器皿

参考例句：

• It used to be a crystal stream.那曾是条清澈见底的小溪。
• Those fine wine glasses are made of crystal.那些漂亮的酒杯是用水晶做的。

11 enclosed   

adj.被附上的；（用墙等）围住的；封闭的；与外界隔绝的v.（用墙、篱笆等）把…围起来( enclose的过去式和过去分词 )；把…装入信封；附入；（尤指墙、篱笆等 ）围住

参考例句：

• The yard had been enclosed with iron railings. 院子用铁栅栏围了起来。
• Do not use this substance in an enclosed space. 切勿在不透气的地方使用此物质。

12 dome   

n.圆屋顶，拱顶

参考例句：

• The dome was supported by white marble columns.圆顶由白色大理石柱支撑着。
• They formed the dome with the tree's branches.他们用树枝搭成圆屋顶。

13 intense   

adj.认真的，专注的；强烈的；紧张的；热情的

参考例句：

• Susan was an intense young lady.苏珊是一个热情的年轻姑娘。
• The quarrel caused her intense unhappiness.争吵令她极其不快。

14 nutrients   

n.（食品或化学品）营养物，营养品( nutrient的名词复数 )

参考例句：

• a lack of essential nutrients 基本营养的缺乏
• Nutrients are absorbed into the bloodstream. 营养素被吸收进血液。 来自《简明英汉词典》

15 reptiles   

n.爬行动物，爬虫( reptile的名词复数 )

参考例句：

• Snakes and crocodiles are both reptiles. 蛇和鳄鱼都是爬行动物。 来自《简明英汉词典》
• Birds, reptiles and insects come from eggs. 鸟类、爬虫及昆虫是卵生的。 来自《现代汉英综合大词典》

16 lizards   

n.蜥蜴( lizard的名词复数 )

参考例句：

• Nothing lives in Pompeii except crickets and beetles and lizards. 在庞培城里除了蟋蟀、甲壳虫和蜥蜴外，没有别的生物。 来自辞典例句
• Can lizards reproduce their tails? 蜥蜴的尾巴断了以后能再生吗？ 来自辞典例句

17 stem   

n.茎，干，船首，词干，血统；vt.堵住，阻止，抽去梗；vi.起源于，发生

参考例句：

• Cut the stem cleanly,just beneath a leaf joint.把茎切整齐点，正好切在叶根下。
• The ship was in a blaze from stem to stern.整艘船从头到尾都着火了。

18 planet   

n.行星

参考例句：

• Neptune is the furthest planet from the sun. 海王星是离太阳最远的行星。
• Rubbish, however, is only part of the problem of polluting our planet. 然而, 垃圾只是我们这个星球的污染问题的一个方面。

19 overnight   

ad.前一天晚上，一夜间 a.前一天晚上的

参考例句：

• She stayed overnight in the hotel. 她在旅馆过了一夜。
• Our success is not won overnight. 我们的成功不是一夜之间得来的。

20 Celsius   

adj.摄氏温度计的，摄氏的

参考例句：

• The temperature tonight will fall to seven degrees Celsius.今晚气温将下降到七摄氏度。
• The maximum temperature in July may be 36 degrees Celsius.七月份最高温度可能达到36摄氏度。

21 missile   

n.导弹，投射物

参考例句：

• The missile curved gracefully towards its target.导弹呈优美的曲线状飞向目标。
• We got a fix on the missile launching site.我们确定了导弹发射场的位置。

22 captured   

俘获( capture的过去式和过去分词 )； 夺取； 夺得； 引起（注意、想像、兴趣）

参考例句：

• Allied troops captured over 300 enemy soldiers. 盟军俘虏了300多名敌方士兵。
• Most of the rebels were captured and disarmed. 大部分叛乱分子被俘获并解除了武装。

23 experimental   

adj.实验的，用作实验的，根据实验的

参考例句：

• This trip will be only experimental.这次旅行只是试验性的。
• The experimental farm is near the waterpower station.实验农场靠近水电站。

24 users   

用户，使用者( user的名词复数 )

参考例句：

• The new software will prove a boon to Internet users. 这种新软件将会对互联网用户大有益处。
• Ramps should be provided for wheelchair users. 应该给轮椅使用者提供坡道。