VOA慢速英语 2007 1003b

VOICE ONE:

I'm Shirley Griffith.

VOICE TWO:

And I'm Steve Ember with EXPLORATIONS in VOA Special English. Today we tell about an unusual scientific research area in the United States. 

 
 
It is filled with the remains¹ of ancient animals.  This unusual place is in the center of Los Angeles, California.  Its name is Rancho La Brea.  But most people know it as the La Brea Tar² Pits⁴.

(MUSIC) 

VOICE ONE:

To understand why La Brea is an important scientific research center we must travel back through time almost forty thousand years.  Picture an area that is almost desert land.  The sun is hot.  A pig-like creature searches for food.  It uses its short, flat nose to dig near a small tree.  It moves small amounts of sand with its nose.  It finds nothing.  The pig starts to walk away, but it cannot move its feet. 

They are covered with a thick, black substance.  The pig shakes one foot loose, but the others just sink deeper.  The more it struggles against the black substance, the deeper it sinks.  The pig attempts to free itself again and again.  It now screams in fear and fights wildly to get loose. Less than a kilometer away, a huge cat-like creature with two long front teeth hears the screams.  It, too, is hungry.  Traveling across the ground at great speed, the cat nears the area where the pig is fighting for its life.

The cat jumps on the pig’s back.  It sinks its long teeth into the pig’s neck.  The pig dies quickly, and the cat begins to eat.  Almost an hour passes before the cat is finished.  When it attempts to leave, like the pig, it finds it cannot move.  The more the big cat struggles, the deeper it sinks into the black substance.

Before morning, the cat is dead.  Its body, and the bones of the pig, slowly sink into the sticky⁵ black hole.

(MUSIC)

VOICE TWO:

Scientists say the story we have told you happened again and again over a period of many thousands of years.  The black substance that trapped the animals came out of the Earth as oil.

The oil dried, leaving behind a partly solid substance called asphalt.  In the heat of the sun, the asphalt softened⁷.  Whatever touched it would often become trapped forever.

In seventeen sixty-nine, a group of Spanish explorers visited the area.  They were led by Gaspar de Portola, governor⁸ of Lower California.

The group stopped to examine the sticky black substance that covered the Earth.  They called the area “La Brea‿the Spanish words for “tar.‿/P>

Many years later, settlers used the tar, or asphalt, on the tops of their houses to keep water out.  They found animal bones in the asphalt, but threw them away. In nineteen-oh-six, scientists began to study the bones found in La Brea.  Ten years later, the owner of the land, George Allan Hancock, gave it to the government of Los Angeles.  His gift carried one condition. He said La Brea could only be used for scientific work.

VOICE ONE:

Today, the La Brea Tar Pits are known to scientists around the world.  The area is considered one of the richest areas of fossil⁹ bones in the world.  It is an extremely valuable place to study ancient animals.  Scientists have recovered more than one million fossil bones from the La Brea Tar Pits. They have identified more than six hundred fifty different kinds of animals and plants.  

The fossils¹⁰ are from creatures as small as insects to those that were bigger than a modern elephant.   These creatures became trapped as long ago as forty thousand years.   It is still happening today.  Small birds and animals still become trapped in the La Brea Tar Pits.

(MUSIC)

VOICE TWO:

 
A saber-tooth cat at the Page Museum at the La Brea Tar Pits
Rancho La Brea is the home of a modern research center and museum.  Visitors can see the ancient fossil bones of creatures like the imperial¹¹ mammoth¹² and the American mastodon.  Both look something like the modern day elephant, but bigger.

The museum has many fossil remains of the huge cats that once lived in the area.  They are called saber-toothed cats because of their long, fierce teeth.  Scientists have found more than two thousand examples of the huge cats.  The museum also has many ground sloths¹⁴ and thousands of fossil remains of an ancient kind of wolf.   Scientists believe large groups of wolves became stuck when they came to feed on animals already trapped in the asphalt.

VOICE ONE:

 
Volunteers dig bones from Pit³ 91 at the La Brea Tar Pits
Since nineteen sixty-nine, scientists have been digging at one area of La Brea called Pit Ninety-One. They have found more than forty thousand fossils in Pit Ninety-One.  More than ninety-five percent of the mammal bones are from just seven different animals.  Three were plant-eaters.  They were the western horse, the ancient bison and a two-meter tall animal called the Harlan’s ground sloth¹³.

Four of the animals were meat-eating hunters.  These were the saber-tooth cat, the North American lion, the dire¹⁵ wolf and the coyote.  All these animals, except the dog-like coyote, have disappeared from the Earth.

VOICE TWO:

Researchers say eighty percent of the fossils found are those of meat-eating animals.  They say this is a surprise because there have always been more plant-eaters in the world.  The researchers say each plant-eater that became trapped caused many meat-eaters to come to the place to feed.  They, too, became trapped.

Rancho La Brea has also been a trap for many different kinds of insects.  Scientists free these dead insects by washing the asphalt away with special chemicals.  The La Brea insects give scientists a close look at the history of insects in southern California.

The La Brea Tar Pits have also provided¹⁶ science with interesting information about the plants that grew in the area.  For many thousands of years, plant seeds landed in the sticky asphalt.  The seeds have been saved for research.  Scientists also have found pollen¹⁷ from many different kinds of plants.

The seeds and pollen, or the lack of them, can show severe weather changes over thousands of years. Scientists say these provide information that has helped them understand the history of the environment.  The seeds and pollen have left a forty thousand year record of the environment and weather for this area of California.

VOICE ONE:

Many visitors to the tar pits wonder why they produce large gas bubbles¹⁸. Now scientists from the University of California, Riverside, have the answer.  Bacteria in the natural asphalt are eating away at the oil below the surface and producing methane¹⁹ gas.  The scientists discovered more than two hundred kinds of bacteria.  Most of them were species²⁰ that were unknown.  The bacteria were trapped in soil that was mixed with heavy oil almost twenty-eight thousand years ago.

The bacteria are able to survive in an extreme environment.  The scientists say they live in the asphalt with no water, little or no oxygen and many poisonous chemicals.  Scientists think the discovery of the bacteria might lead to new methods to clean oil spills and other uses.    

(MUSIC)

VOICE TWO:

Thousands of visitors come each year to see the fossils that have been found at Rancho La Brea.  They visit the George C. Page Museum.  Mister²¹ Page was a wealthy man who became very interested in the scientific work being done at the tar pits.  He gave the money to build the museum and research center. 

At the museum, visitors can watch scientists dig bones from La Brea’s Pit Ninety-One.  The scientists dig very slowly, using small tools similar to those used by a doctor to examine teeth.  They also use toothbrushes and cleaning fluids²² to help soften⁶ and clean away the asphalt. 

VOICE ONE:

Visitors to the museum can also see the “fish bowl,‿a laboratory²³ surrounded by glass.  Here, they can watch scientists do their research.  Visitors can watch the scientists clean, examine, repair and identify fossils that are still being discovered. Through this process, scientists are able to answer questions and solve puzzles about animals and their environment from thousands of years ago.

It is exciting to stand only a few meters away and watch scientists clean the asphalt off a fossil that is thousands of years old.  Visitors quickly learn why researchers consider Rancho La Brea a very special place.

(MUSIC)

VOICE TWO:

This program was written by Paul Thompson.  It was produced by Mario Ritter. You can learn more about the La Brea Tar Pits at our Web site, voaspecialenglish.com. I'm Steve Ember.

VOICE ONE:

And I'm Shirley Griffith.  Join us again next week for EXPLORATIONS in VOA Special English.

1 remains   

n.剩余物，残留物；遗体，遗迹

参考例句：

• He ate the remains of food hungrily.他狼吞虎咽地吃剩余的食物。
• The remains of the meal were fed to the dog.残羹剩饭喂狗了。

2 tar   

n.柏油，焦油；vt.涂或浇柏油/焦油于

参考例句：

• The roof was covered with tar.屋顶涂抹了一层沥青。
• We use tar to make roads.我们用沥青铺路。

3 pit   

n.深坑，核，矿井，陷阱，英国剧场正厅后排，凹陷疤痕；vt.使...有伤痕，去...的核，与...较量

参考例句：

• A sheep fell into a pit,and I helped it out.一只羊掉进坑里，我把它弄了出来。
• They dug a pit to bury the rubbish.他们挖了一个坑把垃圾埋掉。

4 pits   

n.井( pit的名词复数 )；煤矿；麻子；（赛车道旁的）修理加油站

参考例句：

• The wood is full of pits and needs sanding. 这木料上到处是凹坑，需用砂纸打磨一下。 来自《现代汉英综合大词典》
• The comedian's performance was the pits! 这喜剧演员的表演糟透了。 来自《简明英汉词典》

5 sticky   

adj.粘的，闷热的，困难的，令人不满意的

参考例句：

• This paste is not sticky enough.这糨糊不黏。
• Here is a sticky business!这事真难办！

6 soften   

v.(使)变柔软；(使)变柔和

参考例句：

• Plastics will soften when exposed to heat.塑料适当加热就可以软化。
• This special cream will help to soften up our skin.这种特殊的护肤霜有助于使皮肤变得柔软。

7 softened   

（使）变软( soften的过去式和过去分词 )； 缓解打击； 缓和； 安慰

参考例句：

• His smile softened slightly. 他的微笑稍柔和了些。
• The ice cream softened and began to melt. 冰淇淋开始变软并开始融化。

8 governor   

n.统治者，地方长官(如省长，州长，总督等)

参考例句：

• The governor was an expert at fencing with reporters.这位州长是搪塞新闻记者的能手。
• He was elected governor of the state of California.他当选为加州州长。

9 fossil   

n.化石，食古不化的人，老顽固

参考例句：

• At this distance of time it is difficult to date the fossil.时间隔得这么久了，很难确定这化石的年代。
• The man is a fossil.那人是个老顽固。

10 fossils   

n.化石( fossil的名词复数 )；老顽固；食古不化的人；老古董（老人）

参考例句：

• fossils over two million years old 两百多万年的化石
• The geologist found many uncovered fossils in the valley. 在那山谷里，地质学家发现了许多裸露的化石。 来自《简明英汉词典》

11 imperial   

adj.帝王的，至尊的；n.特等品

参考例句：

• They made an objection to the imperial system with resolution.他们坚决反对帝制。
• The Prince Imperial passed away last night.皇太子昨晚去世了。

12 mammoth   

n.长毛象；adj.长毛象似的，巨大的

参考例句：

• You can only undertake mammoth changes if the finances are there.资金到位的情况下方可进行重大变革。
• Building the new railroad will be a mammoth job.修建那条新铁路将是一项巨大工程。

13 sloth   

n.[动]树懒；懒惰，懒散

参考例句：

• Absence of competition makes for sloth.没有竞争会导致懒惰。
• The sloth spends most of its time hanging upside down from the branches.大部分时间里树懒都是倒挂在树枝上。

14 sloths   

懒散( sloth的名词复数 )； 懒惰； 树獭； （经济）停滞。

参考例句：

• Mummies of pleistocene ground sloths, with original skin, hair, tendons and claws have been found. 还发现了保存原有皮肤，毛发，腱和爪的更新世时期地面树懒的木乃伊。
• He was inspired by fossils of armadillos and sloths. 犰狳和树懒化石让他获得了灵感。

15 dire   

adj.可怕的，悲惨的，阴惨的，极端的

参考例句：

• There were dire warnings about the dangers of watching too much TV.曾经有人就看电视太多的危害性提出严重警告。
• We were indeed in dire straits.But we pulled through.那时我们的困难真是大极了，但是我们渡过了困难。

16 provided   

conj.假如，若是；adj.预备好的，由...供给的

参考例句：

• Provided it's fine we will have a pleasant holiday.如果天气良好，我们的假日将过得非常愉快。
• I will come provided that it's not raining tomorrow.如果明天不下雨，我就来。

17 pollen   

n.[植]花粉

参考例句：

• Hummingbirds have discovered that nectar and pollen are very nutritious.蜂鸟发现花蜜和花粉是很有营养的。
• He developed an allergy to pollen.他对花粉过敏。

18 bubbles   

泡( bubble的名词复数 )； 泡影； 肥皂泡； （欲表达的）一点感情

参考例句：

• Bubbles are rising from the bottom of the boiling water. 水泡从沸水的底部升到水面。
• The incorporation of air bubbles in the glass spoiled it. 玻璃含有气泡，使它质量降低。

19 methane   

n.甲烷，沼气

参考例句：

• The blast was caused by pockets of methane gas that ignited.爆炸是由数袋甲烷气体着火引起的。
• Methane may have extraterrestrial significance.甲烷具有星际意义。

20 species   

n.物种，种群

参考例句：

• Are we the only thinking species in the whole of creation?我们是万物中惟一有思想的物种吗？
• This species of bird now exists only in Africa.这种鸟现在只存在于非洲。

21 mister   

n.(略作Mr.全称很少用于书面)先生

参考例句：

• Mister Smith is my good friend.史密斯先生是我的好朋友。
• He styled himself " Mister Clean ".他自称是“清廉先生”。

22 fluids   

n.液体，流体( fluid的名词复数 )

参考例句：

• He is taking cold fluids. 他正在喝冷饮。 来自《简明英汉词典》
• You can contract Aids if your bodily fluids come into contact with the bodily fluids of someone else who is infected with HIV. 如果你的体液与染有HIV者的体液接触，你就会染上艾滋病。 来自《简明英汉词典》

23 laboratory   

n.实验室，化验室

参考例句：

• She has donated money to establish a laboratory.她捐款成立了一个实验室。
• Our laboratory equipment isn't perfect,but we must make do.实验室设备是不够理想，但我们只好因陋就简。