VOA慢速英语 2008 0108b

VOICE ONE:

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

VOICE TWO:

 
Emergency hospital during 1918 influenza² epidemic³, Camp Funston, Kansas 
And I'm Faith Lapidus.  This week, our subject is influenza, commonly called the flu.  Winter officially arrived in northern areas of the world last month.  Medical experts have another name for the start of winter -- the flu season. 

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VOICE ONE:

Influenza is a common infection of the nose and throat, and sometimes the lungs.  The cause is a virus that passes from one person to another.  The virus spreads through the air when an infected person expels⁴ air suddenly. 

Influenza develops after the virus enters a person's nose or mouth.  The flu causes muscle pain, sudden high body temperature, breathing problems and weakness.  Generally, most people feel better after a week or two.  But the flu can kill.  It is especially dangerous to the very young, the very old and those with weakened⁵ defenses against disease⁷.

The World Health Organization says the influenza virus infects up to five million people around the world each year.  Between two hundred fifty thousand and five hundred thousand people die every year from influenza.

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VOICE TWO:

Medical experts have recognized for some time that people become infected with influenza during the winter months.  But they did not really know why until recently.

American researchers say they now know why the influenza virus spreads in the winter and not in the summer.  They say it is because the virus remains⁸ in the air longer when the air is cold and dry.

Researchers in New York carried out twenty experiments with guinea pigs to investigate how the virus spreads.  First, they confirmed that the guinea pigs could develop the flu and pass it on to others.  The researchers then placed the animals in areas where the virus was present in the air.  Then they changed the temperature and humidity⁹ levels of their environments.  Humidity is the amount of wetness in the air. 

VOICE ONE:

The researchers found the virus spread the most when the temperature was about five degrees Celsius¹⁰ and the humidity was twenty percent.  Few of the guinea pigs developed influenza as the temperature increased.  The virus stopped spreading completely at thirty degrees Celsius and eighty percent humidity.  The researchers also found that the animals spread the virus among themselves nearly two days longer when the temperature was low. 

Results of the study were reported in PLoS Pathogens, a publication¹¹ of the Public Library of Science. 

VOICE TWO:

One of the researchers said the study shows that influenza virus is more likely to infect people during an outdoor walk on a cold day than in a warm room.  He said cold air helps the virus survive in the air and low humidity helps it stay there longer.  That is because particles¹² of the virus ride on the extremely small drops of water floating in the air.  When the air is very humid, water droplets¹³ fall to the ground more quickly.

The researchers say, however, that people should not stay in warm places all the time in cold weather to avoid the flu.  They say the best way to prevent the sickness is to get yearly¹⁴ injections¹⁵ of a vaccine¹⁶ that prevents influenza.

VOICE ONE:

Medical experts have identified three major kinds of influenza.  They call them type A, B and C.  Type C is the least serious.  People may not even know they have it.  But researchers study the other two kinds very closely¹⁷.  Viruses change to survive.  This can make it difficult for the body to recognize and fight an infection.

A person who has suffered one kind of flu cannot develop that same kind again.  The body's defense⁶ system produces antibodies.  These substances stay in the blood and destroy the virus if it appears again.  But the body may not recognize a flu virus that has even a small change.

Each year, researchers develop vaccines¹⁸ to prevent the spread of the flu virus.  The World Health Organization holds meetings in which experts discuss what kinds of flu viruses to include in the next vaccine. 

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VOICE TWO:

Historical records have described sicknesses believed to be influenza for more than two thousand years.  The Roman historian¹⁹ Livy described such a disease attacking the Roman army.  People in fifteenth century Italy thought sicknesses were caused by the influence of the stars.  So they called it, "influenza."

In seventeen eighty-one, influenza moved from Europe to North America to the West Indies and Latin²⁰ America.  The flu spread in Asia in eighteen twenty-nine, then again in eighteen thirty-six.  It also traveled to Southeast Asia, Russia and the United States.

VOICE ONE:

In eighteen eighty-nine, the flu began in Central Asia, spread north into Russia, east to China and west to Europe.  Later, it affected²¹ people in North America and Africa.  Experts say two hundred fifty thousand people died in Europe in that flu pandemic.  Around the world, the number was at least one million.

The deadliest spread of influenza ever reported involved a flu that first appeared in Spain.  The Spanish flu killed between twenty million and fifty million people around the world in nineteen-eighteen and nineteen-nineteen.  Even young, healthy people became sick and died in just a few days.

VOICE TWO:

Periods when diseases²² spread around the world are called pandemics.  The World Health Organization says the next flu pandemic is likely to kill as many as six hundred fifty thousand people in industrial countries.  But it says the greatest effect will likely be in developing countries.  The W.H.O. notes that health resources in those countries are limited, and people there are weakened by poor health and diet.

Researchers say the new kind of flu will appear unexpectedly²³.  They will not have enough time to identify it and produce a vaccine.  That is why they are developing faster ways to produce vaccines.

Eighty years ago, the flu virus took months to spread around the world.  Today, airplane travel means a virus can spread to far around the world in just days. 

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VOICE ONE:

Last year, the World Health Organization said the world is closer to a pandemic of the influenza virus than at any time since nineteen sixty-eight.  The flu virus would spread quickly to large numbers of people in many countries.  The pandemic threat is the h-five n-one influenza virus, also known as the bird flu.

Wild and farm birds often have a flu virus.  Yet they usually are able to carry the virus without getting sick.  In nineteen ninety-seven, six people in Hong Kong died of the h-five n-one virus.  The Hong Kong government quickly ordered the killing²⁴ of all farm birds there.  That stopped the spread of h-five n-one to people in Hong Kong. 

Yet the virus had already spread to other parts of Asia.  It was found in sixteen countries between two thousand three and two thousand six.

VOICE TWO:

The WHO says the bird flu virus had infected a total of three hundred thirty-eight people by December twelfth.  Two hundred eight of them died.  Yet fewer people were infected with bird flu or died of it last year than in two thousand six.

These numbers show that the deadly bird flu virus is not spreading among people very easily.  But that could change.  Researchers are worried about the virus changing so that it could spread from person to person.  People would become infected with a virus their bodies have never before experienced²⁵.  They would have no protection.

VOICE ONE:

Researchers are attempting to develop a vaccine to protect against bird flu.  Still, they know that any vaccine would not be ready until a pandemic had already begun. 

Some British researchers say people should be told to wear physical barriers against infectious²⁶ diseases, like masks on the face or gloves to protect the hands.  The researchers examined fifty-one published studies on the effect of simple ways to prevent throat and lung infections.  They found that hand-washing, wearing masks and using gloves each stopped the spread of viruses.  The researchers also found that such physical barriers were even more effective when used together.  They said these simple, low-cost measures could prove to be an easy way to prevent the spread of deadly viruses.

(MUSIC)

VOICE TWO:

This SCIENCE IN THE NEWS program was written by Nancy Steinbach.  Our producer was Brianna Blake.  I'm Faith Lapidus.

VOICE ONE:

And I'm Bob Doughty.  Read and listen to our programs at voaspecialenglish.com.  Join us 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 epidemic   

n.流行病；盛行；adj.流行性的，流传极广的

参考例句：

• That kind of epidemic disease has long been stamped out.那种传染病早已绝迹。
• The authorities tried to localise the epidemic.当局试图把流行病限制在局部范围。

4 expels   

驱逐( expel的第三人称单数 )； 赶走； 把…除名； 排出

参考例句：

• Dean Corso: [expels a lungful of smoke, unmoved] Ten. 迪安科索：[无动于衷的吸了一口烟]一成。
• The average cow expels600 liters of methane a day. 一般每头牛每天会排出600升甲烷。

5 weakened   

adj.虚弱的v.（使）削弱， （使）变弱( weaken的过去式和过去分词 )

参考例句：

• The team has been weakened by injury. 这个队因伤实力减弱。
• In his weakened condition, he is very susceptible to cold. 他身体很弱，因此很容易患感冒。 来自《简明英汉词典》

6 defense   

n.防御，保卫；[pl.]防务工事；辩护，答辩

参考例句：

• The accused has the right to defense.被告人有权获得辩护。
• The war has impacted the area with military and defense workers.战争使那个地区挤满了军队和防御工程人员。

7 disease   

n.疾病，弊端

参考例句：

• The doctors are trying to stamp out the disease.医生正在尽力消灭这种疾病。
• He fought against the disease for a long time.他同疾病做了长时间的斗争。

8 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。

9 humidity   

n.湿度，潮湿，湿气

参考例句：

• The house is not comfortable tonight ,because of the high humidity.由于湿度高，今晚屋子里不舒服。
• It's difficult to work because of the humidity.由于空气潮湿，工作很困难。

10 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。

11 publication   

n.出版，发行；出版；公布，发表

参考例句：

• They don't think this article is suitable for publication.他们认为这篇文章不宜发表。
• The government has delayed publication of the trade figures.政府已将贸易统计数字延后公布。

12 particles   

微粒( particle的名词复数 )； 颗粒； 极少量； 小品词

参考例句：

• These small particles agglomerate together to form larger clusters. 这些颗粒聚结形成较大的团。
• The nucleus of an atom consists of neutrons, protons and other particles. 原子核由中子、质子和其他粒子构成。

13 droplets   

n.小滴( droplet的名词复数 )

参考例句：

• Droplets of sweat were welling up on his forehead. 他额头上冒出了滴滴汗珠。 来自辞典例句
• In constrast, exhaled smoke contains relatively large water droplets and appears white. 相反，从人嘴里呼出的烟则包含相当大的水滴，所以呈白色。 来自辞典例句

14 yearly   

adj.每年的，一年一度的；adv.一年一次地

参考例句：

• The flower show is a yearly event in our town.我们镇上的花展一年举行一次。
• The yearly rental of her house is 2400 yuan.她这房子年租金是2400元。

15 injections   

n.注射( injection的名词复数 )；（液体）注入；喷入；大量资金的投入

参考例句：

• The doctor was associated in the child's mind with injections and pains. 在孩子的心里，医生总是使他联想到打针与疼痛。 来自《简明英汉词典》
• Injections of vitamin C are obviously advantageous. 注射维生素C显然是有利的。 来自《简明英汉词典》

16 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。

17 closely   

adv.紧密地；严密地，密切地

参考例句：

• We shall follow closely the development of the situation.我们将密切注意形势的发展。
• The two companies are closely tied up with each other.这两家公司之间有密切联系。

18 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。

19 historian   

n.历史学家，编史家

参考例句：

• As a historian,he was most typical of the times in which he lived.作为历史学家，他是他所处时代最有代表性的人物。
• He calls himself a historian,but his books are a mere journalism.他自称为历史学家，但是他的书都是些肤浅的通俗作品。

20 Latin   

adj.拉丁的，拉丁语的，拉丁人的；n.拉丁语

参考例句：

• She learned Latin without a master.她无师自通学会了拉丁语。
• Please use only Latin characters.请仅使用拉丁文字符。

21 affected   

adj.不自然的，假装的

参考例句：

• She showed an affected interest in our subject.她假装对我们的课题感到兴趣。
• His manners are affected.他的态度不自然。

22 diseases   

n.疾病( disease的名词复数 )；弊端；恶疾；痼疾

参考例句：

• Smoking is a causative factor in several major diseases. 抽烟是引起几种严重疾病的病因。
• The illness frequently coexists with other chronic diseases. 这种病往往与其他慢性病同时存在。

23 unexpectedly   

adv.未料到地，意外地；竟；居然；骤然

参考例句：

• The volcano unexpectedly blew up early in the morning. 火山一早突然爆发了。
• I had just put the dinner on when Jim walked in unexpectedly. 我刚把晚饭摆上桌，吉姆突然走进来。

24 killing   

n.巨额利润；突然赚大钱，发大财

参考例句：

• Investors are set to make a killing from the sell-off.投资者准备清仓以便大赚一笔。
• Last week my brother made a killing on Wall Street.上个周我兄弟在华尔街赚了一大笔。

25 experienced   

adj.有经验的；经验丰富的，熟练的

参考例句：

• Experienced seamen will advise you about sailing in this weather.有经验的海员会告诉你在这种天气下的航行情况。
• Perhaps you and I had better change over;you are more experienced.也许我们的工作还是对换一下好，你比我更有经验。

26 infectious   

adj.传染的，有传染性的，有感染力的

参考例句：

• Influenza is an infectious disease.流感是一种传染病。
• What an infectious laugh she has!她的笑声多么具有感染力啊！