英语听力精选进阶版 13315

Secrets of the plague

14 October 2011

The genetic¹ code of the germ that caused the Black Death has been reconstructed by scientists for the first time.

The Black Death, also known as the plague, killed millions of people in Europe in the 14th Century.

Reporter:

Matt McGrath

Skeletons of plague victims 

DNA² samples were taken from skeletons found in London

Report

Humans have rarely encountered an enemy as devastating³ as the bacterium⁴, Yersinia pestis. Between 1347 and 1351 it sparked the Black Death, an infection carried by fleas⁵ that spread rapidly across Europe killing⁶ around 50 million people.

Now scientists have uncovered some of the genetic secrets of the plague, thanks to DNA fragments drilled from the teeth of victims buried in a graveyard⁷ in East London.

The researchers say that all current strains circulating in the world are directly related to the medieval bacterium. And while the infection still kills 2,000 people globally every year, it's much less of a threat because our immune systems have adapted to it.

The scientists say the techniques used to rebuild the genome of the Black Death could now be used to reconstruct other ancient pathogens

Matt McGrath, BBC World Service

1 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。

2 DNA   

(缩)deoxyribonucleic acid 脱氧核糖核酸

参考例句：

• DNA is stored in the nucleus of a cell.脱氧核糖核酸储存于细胞的细胞核里。
• Gene mutations are alterations in the DNA code.基因突变是指DNA密码的改变。

3 devastating   

adj.毁灭性的，令人震惊的，强有力的

参考例句：

• It is the most devastating storm in 20 years.这是20年来破坏性最大的风暴。
• Affairs do have a devastating effect on marriages.婚外情确实会对婚姻造成毁灭性的影响。

4 bacterium   

n.(pl.)bacteria 细菌

参考例句：

• The bacterium possibly goes in the human body by the mouth.细菌可能通过口进入人体。
• A bacterium is identified as the cause for his duodenal ulcer.一种细菌被断定为造成他十二指肠溃疡的根源。

5 fleas   

n.跳蚤( flea的名词复数 )；爱财如命；没好气地（拒绝某人的要求）

参考例句：

• The dog has fleas. 这条狗有跳蚤。
• Nothing must be done hastily but killing of fleas. 除非要捉跳蚤，做事不可匆忙。 来自《简明英汉词典》

6 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。

7 graveyard   

n.坟场

参考例句：

• All the town was drifting toward the graveyard.全镇的人都象流水似地向那坟场涌过去。
• Living next to a graveyard would give me the creeps.居住在墓地旁边会使我毛骨悚然。