VOA慢速英语 2008 1104b

VOICE ONE:

This is SCIENCE IN THE NEWS in VOA Special English. I'm Bob Doughty¹.

VOICE TWO:

And I'm Barbara Klein. This week, we will tell about mammal populations in danger of disappearing. We will also tell about one kind of animal that disappeared long ago. And, we will examine some traditional beliefs about the viruses that cause influenza² and the common cold.

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VOICE ONE:
　
The Iberian lynx is called critically endangered

A worldwide study has found that almost twenty-five percent of wild mammals are in danger of permanently³ disappearing. Scientific researchers considered all known mammal populations. The researchers say permanent disappearance⁴ threatens at least one thousand one hundred forty-one species⁵ or groups of animals. Mammals are the closest relatives to human beings.

The researchers are blaming loss of habitat, or living space, and hunting for threatened land mammals. They say water mammals suffer more from pollution, being hit by ships and caught in fishing nets.

VOICE TWO:

One thousand seven hundred experts worked on the study. They are from one hundred thirty countries. Their findings were reported at the World Conservation Conference of the International Union for Conservation of Nature in Barcelona, Spain.

The report was presented in connection with the Red List of Threatened Species. The World Conservation Conference announces the Red List each year. The list contains almost forty five thousand animals and plants. Of those, almost seventeen thousand, or about thirty eight percent, are threatened with extinction⁷.

Some scientists say the report provides evidence that Earth's wildlife is going through widespread extinction. The last such period may have taken place millions of years ago, when dinosaurs⁸ became extinct⁶.

VOICE ONE:

Jan Schipper led the writing of the report. He directs the I.U.C.N.'s program that observes animal populations worldwide.

Mister Schipper says up to thirty six percent of mammals could be facing extinction. He says this is true because not much information exists about some species. At least seventy-six mammals have permanently disappeared since fifteen hundred.

The director general of the I.U.C.N., Julia Marton-Lefevre, says human activity could cause loss of hundreds of species. She says that is a frightening sign of what is happening to habitats. Still, the report said human efforts also could help save some species. Miz Marton-Lefevre is calling for action to make that happen.

VOICE TWO:

For study purposes, the I.U.C.N. divides animals into groups. The scientists call animals that have disappeared, or almost disappeared, extinct or nearly extinct. A frog-like creature called Holdridge's toad⁹ was declared extinct. It lived only in Costa Rica.

Other divisions depend on the amount of threat the animals face. The animals in most danger are considered critically endangered.

For example, the Iberian lynx is called critically endangered. As few as eighty-four adult members of the large, cat-like animals remain alive.

The Red List identifies the second most threatened animals as endangered. The scientists named a Southeast Asian animal, the fishing cat, as among the endangered. Part of the fishing cat's wetland habitat no longer exists.

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VOICE ONE:

A new study suggests the last woolly mammoths in Siberia were native to North America. Scientists had believed these mammoths came from Europe or Asia.

The study involved genetic¹¹ evidence from the remains¹² of the ancient animal. Woolly Mammoths share an ancestor with modern-day elephants. The mammoth¹⁰ is recognizable for its long hair and large tusks¹³.

VOICE TWO:

Woolly mammoths disappeared thousands of years ago, after Earth's most recent ice age. But mammoths were able to survive for thousands of years. During this period, they slowly changed to live in extremely cold climates.

Scientists believe the ancestors of woolly mammoths came from Africa. As the African mammoths moved north to Eurasia, scientists believe, they grew long hair to protect them from the extreme cold of Siberia.

VOICE ONE:

To better understand these animals, an international research team examined genetic material from more than one hundred woolly mammoth remains. The remains were found in North America, Europe and Asia. These fossils¹⁴ came from woolly mammoths that lived between forty-four thousand and eleven thousand years ago.

Hendrik Poinar is a molecular¹⁵ evolutionary¹⁶ geneticist at McMaster University in Ontario, Canada. He and his team examined genetic material from fossilized teeth and pieces of bones from woolly mammoths. They also examined results of earlier woolly mammoth studies.

VOICE TWO:

Until recently, many scientists believed that mammoths came from Europe and Asia because that is where the oldest fossils were found. Earlier studies of the mammoths involved only one continent at a time. The researchers discovered that mammals traveled back and forth¹⁷ several times between Eurasia and Alaska over thousands of years. The animals were able to travel on a land bridge that connected Siberia and Alaska during low sea levels.

VOICE ONE:

The researchers discovered that the mammoths were divided in three major groups. One group lived mainly in Asia. Another group lived mainly in the Americas. And, a third group lived in both places. They believe the American mammoths traveled back across the Bering Strait and in time replaced the other populations of mammoths.

The researchers believe the animals moved the great distances in search of food. A report with their findings was published in Current Biology. Other researchers disputed the findings. They say the study is based on only limited information.

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VOICE TWO:

Autumn and winter are cold and flu season -- when people are most likely to catch the viruses that cause influenza and the common cold.

Is the old advice true that wearing warm clothing will help prevent a cold? Or if you do get sick, should you follow the old saying, "Feed a cold and starve a fever"? And what about that fever? Should you take medication to reduce your temperature, or is it better to let the body treat the infection itself?

Everyone seems to have an answer. But how much value is there in popular wisdom?

VOICE ONE:

Doctor Alvin Nelson El Amin knows a lot about cold and flu season. He is medical director of the immunization program for the Los Angeles County Department of Public Health in California.

Doctor Nelson El Amin says studies may be just starting to provide evidence for long-held beliefs. For example, scientists for years dismissed the idea that getting cold and wet might cause colds or flu.

But recent studies have shown that cold temperatures cause stress on the body. That stress can create conditions more inviting¹⁸ to viruses. So maybe it does make sense to wrap up warmly before leaving home.

VOICE TWO:

And what about the advice to feed a cold and starve a fever? Doctor Nelson El Amin says you should eat if you have a cold and are hungry. But a higher than normal body temperature suggests a more serious problem. He says people are usually not hungry anyway when they have a high fever. Eating might even cause a person to vomit¹⁹. But drinking plenty of liquids is important. A fever can easily dehydrate²⁰ the body.

Finally, when should you treat a fever? Doctor Nelson El Amin says a fever should be treated if it stays at forty degrees centigrade or above for a day or more. A temperature that high can damage brain cells. The doctor also believes in treating a fever if it prevents a person from sleeping.

VOICE ONE:

Aspirin²¹, acetaminophen and ibuprofen can all be used to reduce pain and fever. But aspirin should not be given to children because it can cause a rare condition.

One belief that Doctor Nelson El Amin wanted to make clear is wrong is that influenza vaccine²² can cause the flu. It cannot. Sometimes people get the flu from another person soon after they get vaccinated²³, so they blame the vaccine, he says.

But, flu vaccines²⁴ do not protect everyone who gets them. Still, even if a person does get sick, the vaccine can limit the effects of the virus.

(MUSIC)

VOICE TWO:

This SCIENCE IN THE NEWS was written by Jerilyn Watson, Caty Weaver²⁵ and Brianna Blake, who also was our producer. I'm Barbara Klein.

VOICE ONE:

And I'm Bob Doughty. Read and listen to our programs at voaspecialenglish.com. Listen again next week for more news about science, in Special English, on the Voice of America.

 

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 influenza   

n.流行性感冒，流感

参考例句：

• They took steps to prevent the spread of influenza.他们采取措施
• Influenza is an infectious disease.流感是一种传染病。

3 permanently   

adv.永恒地，永久地，固定不变地

参考例句：

• The accident left him permanently scarred.那次事故给他留下了永久的伤疤。
• The ship is now permanently moored on the Thames in London.该船现在永久地停泊在伦敦泰晤士河边。

4 disappearance   

n.消失，消散，失踪

参考例句：

• He was hard put to it to explain her disappearance.他难以说明她为什么不见了。
• Her disappearance gave rise to the wildest rumours.她失踪一事引起了各种流言蜚语。

5 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。

6 extinct   

adj.灭绝的，不再活跃的，熄灭了的，已废弃的

参考例句：

• All hopes were extinct.所有希望都破灭了。
• Dinosaurs have been extinct for millions of years.恐龙绝种已有几百万年了。

7 extinction   

n.熄灭，消亡，消灭，灭绝，绝种

参考例句：

• The plant is now in danger of extinction.这种植物现在有绝种的危险。
• The island's way of life is doomed to extinction.这个岛上的生活方式注定要消失。

8 dinosaurs   

n.恐龙( dinosaur的名词复数 )；守旧落伍的人，过时落后的东西

参考例句：

• The brontosaurus was one of the largest of all dinosaurs. 雷龙是所有恐龙中最大的一种。 来自《简明英汉词典》
• Dinosaurs have been extinct for millions of years. 恐龙绝种已有几百万年了。 来自《简明英汉词典》

9 toad   

n.蟾蜍，癞蛤蟆

参考例句：

• Both the toad and frog are amphibian.蟾蜍和青蛙都是两栖动物。
• Many kinds of toad hibernate in winter.许多种蟾蜍在冬天都会冬眠。

10 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。

11 genetic   

adj.遗传的，遗传学的

参考例句：

• It's very difficult to treat genetic diseases.遗传性疾病治疗起来很困难。
• Each daughter cell can receive a full complement of the genetic information.每个子细胞可以收到遗传信息的一个完全补偿物。

12 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。

13 tusks   

n.（象等动物的）长牙( tusk的名词复数 )；獠牙；尖形物；尖头

参考例句：

• The elephants are poached for their tusks. 为获取象牙而偷猎大象。
• Elephant tusks, monkey tails and salt were used in some parts of Africa. 非洲的一些地区则使用象牙、猴尾和盐。 来自英语晨读30分（高一）

14 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》

15 molecular   

adj.分子的；克分子的

参考例句：

• The research will provide direct insight into molecular mechanisms.这项研究将使人能够直接地了解分子的机理。
• For the pressure to become zero, molecular bombardment must cease.当压强趋近于零时，分子的碰撞就停止了。

16 evolutionary   

adj.进化的；演化的，演变的；[生]进化论的

参考例句：

• Life has its own evolutionary process.生命有其自身的进化过程。
• These are fascinating questions to be resolved by the evolutionary studies of plants.这些十分吸引人的问题将在研究植物进化过程中得以解决。

17 forth   

adv.向前；向外，往外

参考例句：

• The wind moved the trees gently back and forth.风吹得树轻轻地来回摇晃。
• He gave forth a series of works in rapid succession.他很快连续发表了一系列的作品。

18 inviting   

adj.诱人的，引人注目的

参考例句：

• An inviting smell of coffee wafted into the room.一股诱人的咖啡香味飘进了房间。
• The kitchen smelled warm and inviting and blessedly familiar.这间厨房的味道温暖诱人，使人感到亲切温馨。

19 vomit   

v.呕吐，作呕；n.呕吐物，吐出物

参考例句：

• They gave her salty water to make her vomit.他们给她喝盐水好让她吐出来。
• She was stricken by pain and began to vomit.她感到一阵疼痛，开始呕吐起来。

20 dehydrate   

vt.使脱水

参考例句：

• People can very quickly dehydrate in the desert.人在沙漠里很快就会脱水。
• Without these structures, many warm-blooded animals would quickly dehydrate,especially in dry climates.没有这样的结构，许多温血动物将很快脱水，特别是在干燥的气候条件下。

21 aspirin   

n.阿司匹林

参考例句：

• The aspirin seems to quiet the headache.阿司匹林似乎使头痛减轻了。
• She went into a chemist's and bought some aspirin.她进了一家药店，买了些阿司匹林。

22 vaccine   

n.牛痘苗，疫苗；adj.牛痘的，疫苗的

参考例句：

• The polio vaccine has saved millions of lives.脊髓灰质炎疫苗挽救了数以百万计的生命。
• She takes a vaccine against influenza every fall.她每年秋季接种流感疫苗。

23 vaccinated   

[医]已接种的，种痘的，接种过疫菌的

参考例句：

• I was vaccinated against tetanus. 我接种了破伤风疫苗。
• Were you vaccinated against smallpox as a child? 你小时候打过天花疫苗吗？

24 vaccines   

疫苗，痘苗( vaccine的名词复数 )

参考例句：

• His team are at the forefront of scientific research into vaccines. 他的小组处于疫苗科研的最前沿。
• The vaccines were kept cool in refrigerators. 疫苗放在冰箱中冷藏。

25 weaver   

n.织布工；编织者

参考例句：

• She was a fast weaver and the cloth was very good.她织布织得很快，而且布的质量很好。
• The eager weaver did not notice my confusion.热心的纺织工人没有注意到我的狼狈相。