英语听力精选进阶版 7169（在线收听）

Background：科学家们最近在研究新一代的抗生素。这种抗生素将会使用一种在地球上存活了2亿多年的动物 – 青蛙。科学家们将从青蛙体内自身的抵抗系统里提炼出一种天然抗生素。

Frogs protect themselves by secreting chemicals that kill germs on their skin. So the theory is that some of these chemicals could be used as antibiotics.

To find out, researchers in the United Arab Emirates asked colleagues across the world to swab any frogs they found and send them their secretions. They received samples from more than six thousand different species and identified more than a hundred germ-killing chemicals.

Because they've not been used to combat human diseases before, it's hoped that they might be able to kill bacteria that had become drug-resistant.

One problem though is that many of these newly-identified chemicals are toxic. So the next step will be to adapt them to make them benign to patients but lethal to bacteria.

The researchers point out that their work highlights the importance of preserving frog diversity. They say that many species whose skin might contain potentially valuable medicinal substances may become extinct soon because of a loss of habitat and water pollution.

Glossary 词汇表

to secrete something（指动物或植物器官)分泌 

germs 细菌 

antibiotics 抗生素 

to swab something （医学检验）涂片 

sample 采样 

species 物种 

to combat something 与…斗争 

drug-resistant 抗药的，耐药的 

toxic 有毒的 

benign 有益的，良性的 

bacteria （复数）细菌 

to highlight something 强调，突出 

to preserve something 保护 

diversity 多样性 

extinct 灭绝 

habitat 栖息处

Questions and Answers

How might frogs be useful to human medicine? 

Scientists think the chemicals that frogs use on their skin could be used to create new medicines.

What is the advantage of developing new antibiotics? 

They might be used against diseases that can overcome existing drugs.

Are these frog chemicals safe for humans? 

No, many of these chemicals are toxic and they need to be adapted to make them safe or benign.

True or false: The researchers say that it is important for there be a wide range of frog species. 

True, that is what is meant by "frog diversity".