英语听力精选进阶版 7215

Background: 科学家们研究出一项新的方式来估计在地球上生物的总数，据统计一共有8百70万种不同类型的生物。这同过去使用的评估方式得到的结果差距很大。科学家们的发现将在网络科研期刊《生物科学公共图书馆》上发表。

It's generally accepted that very many species have yet to be discovered, but until now nobody has devised a reliable way to find out just how many. Suggestions for total numbers have ranged from 3 million to a hundred million, but most of these have been no more than intelligent guesses.

Scientists from the Census¹ of Marine² Life devised a counting method by identifying numerical patterns linking data on known species. They reckon that there should be about 8.7 million types of living organisms, three-quarters of them animals and the rest plants.

However, since the introduction of the current classification system by Carl Linnaeus in 1758, only a million and a quarter have been catalogued.

The scientists warn that human activity is hastening extinctions, and they note a touch wistfully, that many of the hitherto unknown species may vanish before we even know of their existence.

Glossary⁴ 词汇表

to devise 研究出 

reliable 可信的，可靠的 

an intelligent guess 聪明的猜测 

to reckon 估计 

a classification system 分类系统 

to catalogue 分类记载 

to hasten 加速 

wistful 愁闷的，深思的 

hitherto 迄今 

to vanish 消失

Questions:

1. What has been the estimate for the number of species? 

It has varied⁵ from 3 million to one hundred million.

2. How many living beings are animals and how many are plants?

Three-quarters are animals and one-quarter are plants.

3. What could be speeding up the extinction³ of some species? 

According to scientists human activity could bring about the extinction of some species.

4. True or false? Only a small number of species have been catalogued. 

True. According to the report, only a million and a quarter have been catalogued.

1 census   

n.(官方的)人口调查，人口普查

参考例句：

• A census of population is taken every ten years.人口普查每10年进行一次。
• The census is taken one time every four years in our country.我国每四年一次人口普查。

2 marine   

adj.海的；海生的；航海的；海事的；n.水兵

参考例句：

• Marine creatures are those which live in the sea. 海洋生物是生存在海里的生物。
• When the war broke out,he volunteered for the Marine Corps.战争爆发时，他自愿参加了海军陆战队。

3 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。

4 glossary   

n.注释词表；术语汇编

参考例句：

• The text is supplemented by an adequate glossary.正文附有一个详细的词汇表。
• For convenience,we have also provided a glossary in an appendix.为了方便，我们在附录中也提供了术语表。

5 varied   

adj.多样的，多变化的

参考例句：

• The forms of art are many and varied.艺术的形式是多种多样的。
• The hotel has a varied programme of nightly entertainment.宾馆有各种晚间娱乐活动。