VOA慢速英语2010-EXPLORATIONS - Los Angeles' La Brea Tar P

BOB DOUGHTY¹: I'm Bob Doughty.

FAITH LAPIDUS: And I'm Faith Lapidus with EXPLORATIONS in VOA Special English. Today we tell about a scientific research area in the United States. It is filled with the remains² 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 Tar³ Pits⁵.

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BOB DOUGHTY: 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 finds nothing. The pig starts to walk away, but it cannot move its feet.

They are covered with a thick, black substance. The more it struggles against the black substance, the deeper it sinks. It now screams in fear and fights wildly to get loose.

Two volunteers dig for fossils⁷ near the Page Museum at the La Brea Tar Pits in Los Angeles in 2009

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 and kills it. The pig dies quickly, and the cat begins to eat. When it attempts to leave, the cat 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 sticky⁸ black hole.

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FAITH LAPIDUS: 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 softened⁹. 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, governor¹⁰ 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 “the tar.”

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.

BOB DOUGHTY: Today, the La Brea Tar Pits are known to scientists around the world. The area is considered one of the richest areas of fossil⁶ 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 different kinds of animals and plants.

The fossils 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.

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FAITH LAPIDUS: 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 skeleton¹³ of a saber-tooth cat at the Page Museum

The museum also 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 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.

BOB DOUGHTY: In nineteen sixty-nine, scientists began digging at one area of La Brea called Pit⁴ 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 sloth¹⁴.

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.

FAITH LAPIDUS: Researchers say ninety 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.

BOB DOUGHTY: Digging at Pit Ninety-One was recently suspended¹⁸ in order to pay closer to attention to a new discovery called Project Twenty-Three. In two thousand six a nearby art museum began an underground building project.

La Brea scientists had a chance to investigate an area that otherwise would have been impossible to study. This area turned out to be very rich in fossils. So, twenty-three huge containers of tar, clay and mud were removed from the area for research. This is why the project is now known as Project Twenty-Three.

Scientists have fully¹⁹ examined only several boxes of earth and tar. It will take years to complete all of the containers. But scientists have so far counted over seven hundred parts from different organisms²⁰. One huge discovery was the nearly complete skeleton of a male mammoth. Researchers have named the mammoth Zed. This is the largest mammoth ever found in the area.

Rancho La Brea scientists publish an Internet blog that documents this exciting project. It describes in detail the huge amount of work involved in carefully examining the many layers of tar and earth. For example, you can learn about the degreasing machine. Researchers place a big block of tar into the machine. It removes the oily material, leaving behind hundreds of fossils.

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FAITH LAPIDUS: Each year, thousands of visitors come to see the fossils 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.

Visitors to the museum can see the “fish bowl,” a laboratory²² 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. The objects found in Project Twenty-three could double the size of the research center’s collection.

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)

BOB DOUGHTY: This program was written and produced by Dana Demange. I'm Bob Doughty.

FAITH LAPIDUS: And I'm Faith Lapidus. You can find a link to the La Brea Tar Pits blog on our Web site, voaspecialenglish.com. You can also comment on our programs. Join us again next week for EXPLORATIONS in VOA Special English.

 

1 doughty   

adj.勇猛的，坚强的

参考例句：

• Most of successful men have the characteristics of contumacy and doughty.绝大多数成功人士都有共同的特质：脾气倔强，性格刚强。
• The doughty old man battled his illness with fierce determination.坚强的老人用巨大毅力与疾病作斗争。

2 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。

3 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。

4 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。

5 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》

6 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。

7 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》

8 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！

9 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。

10 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。

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 skeleton   

n.骨骼，框架，骨干，梗概，提要

参考例句：

• A long illness made a skeleton out of him.长期的卧病使他骨瘦如柴。
• Her notes gave us just the bare skeleton of her theory.她的笔记只给我们提供了她的理论的梗概。

14 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。

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 suspended   

a.被暂时搁置的

参考例句：

• A lamp was suspended from the ceiling. 一盏吊灯悬在天花板上。
• The British government has now suspended humanitarian aid to the area. 英国政府现已暂停对这一地区的人道主义援助。

19 fully   

adv.完全地，全部地，彻底地；充分地

参考例句：

• The doctor asked me to breathe in,then to breathe out fully.医生让我先吸气，然后全部呼出。
• They soon became fully integrated into the local community.他们很快就完全融入了当地人的圈子。

20 organisms   

n.有机物( organism的名词复数 )；有机体；生物；有机体系

参考例句：

• The organisms can be divided into discrete categories. 有机体可分为许多互不相联的种类。
• The cell is the unit of which all living organisms are composed. 细胞是构成一切生物的单位。

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 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。