简述灭绝的生物学意义。

for example

in addition

at last

after all

When Carios Westez died at the age of 76． a language died， too． Westez， more commonly known as Red Thunder Cloud， was the last speaker of the Native American language． Catawba． Anyone who wants to hear the songs of the Catawba can contact the Smithsonian Institution in Washington， D．C．， where， back in the 1940s， Red Thunder Cloud recorded a series of songs for future generations． __________（46）They are all that is left of the Catawba language． The language that people used to speak is gone forever． We are all aware of the damage that modern industry can do to the world’s ecology（生态）．However， few people are aware of the impact widely spoken languages have on other languages and ways of life． English has spread all over the world． Chinese， Spanish， Russian， and Hindi have become powerful languages． As well， ___________（47）．When this happens， hundreds of languages that are spoken by only a few die out． Scholars believe there are about 6，000 languages around the world， but more than half of them could die out within the next 100 years． There are many examples， Araki is a native language of the island of Vanuatu， located in the Pacific Ocean． It is spoken by only a few older s，so like Catawba，Araki will soon disappear． Many languages of Ethiopia will have the same fate because each one has only a few speakers． _________（48）In the Americas， 100 languages， each of which has fewer than 300 speakers， also are dying out． Red Thunder Cloud was one of the first to recognize the threat of language death and to try to do something about it． He was not actually born into the Catawba tribe， and the language was not his mother tongue． _________（49）． The songs he sang for the Smithsonian Institution helped to make Native American music popular． Now he is gone， and the language is dead． What does it mean when a language disappears When a plant or insect or animal species dies， it is easy to understand what we’ve been lost and to appreciate what this means for the balance of the natural word． However， language is only a product of the mind． To be the last remaining speaker of a language，like Red Thunder Cloud，must be a lonely destiny， almost as strange and terrible as being the last surviving member of a dying species． ____________（50）

裸蕨纲

石松纲

节蕨纲

真蕨纲

正确

错误

欧洲食用旅鸽

人类大量捕杀旅鸽

旅鸽失去栖息地

利用媒鸽引诱其他旅鸽

胡锦鸟

金色鹦鹉

大海鸟

threaten

threatening

threatened

to threaten

不是

是

Human beings have hastened the disappearance of some.

There was mass extinction long before humanity's time on Earth.

Human beings'activities have had great impact on the earth.

Many species have extinct since the human race came into being.

正确

错误

三叠纪

寒武纪

石炭纪

二叠纪末

Right.

Wrong.

Doesn’t Say.

for example

in addition

at last

after all

When Carios Westez died at the age of 76． a language died， too． Westez， more commonly known as Red Thunder Cloud， was the last speaker of the Native American language． Catawba． Anyone who wants to hear the songs of the Catawba can contact the Smithsonian Institution in Washington， D．C．， where， back in the 1940s， Red Thunder Cloud recorded a series of songs for future generations． __________（46）They are all that is left of the Catawba language． The language that people used to speak is gone forever． We are all aware of the damage that modern industry can do to the world’s ecology（生态）．However， few people are aware of the impact widely spoken languages have on other languages and ways of life． English has spread all over the world． Chinese， Spanish， Russian， and Hindi have become powerful languages． As well， ___________（47）．When this happens， hundreds of languages that are spoken by only a few die out． Scholars believe there are about 6，000 languages around the world， but more than half of them could die out within the next 100 years． There are many examples， Araki is a native language of the island of Vanuatu， located in the Pacific Ocean． It is spoken by only a few older s，so like Catawba，Araki will soon disappear． Many languages of Ethiopia will have the same fate because each one has only a few speakers． _________（48）In the Americas， 100 languages， each of which has fewer than 300 speakers， also are dying out． Red Thunder Cloud was one of the first to recognize the threat of language death and to try to do something about it． He was not actually born into the Catawba tribe， and the language was not his mother tongue． _________（49）． The songs he sang for the Smithsonian Institution helped to make Native American music popular． Now he is gone， and the language is dead． What does it mean when a language disappears When a plant or insect or animal species dies， it is easy to understand what we’ve been lost and to appreciate what this means for the balance of the natural word． However， language is only a product of the mind． To be the last remaining speaker of a language，like Red Thunder Cloud，must be a lonely destiny， almost as strange and terrible as being the last surviving member of a dying species． ____________（50）

裸蕨纲

石松纲

节蕨纲

真蕨纲

正确

错误

欧洲食用旅鸽

人类大量捕杀旅鸽

旅鸽失去栖息地

利用媒鸽引诱其他旅鸽

胡锦鸟

金色鹦鹉

大海鸟

threaten

threatening

threatened

to threaten

不是

是

Human beings have hastened the disappearance of some.

There was mass extinction long before humanity's time on Earth.

Human beings'activities have had great impact on the earth.

Many species have extinct since the human race came into being.

正确

错误

三叠纪

寒武纪

石炭纪

二叠纪末

Right.

Wrong.

Doesn’t Say.