A、People quit their mother tongue but speak in other languages. B、Kids don’t learn the local language of their parents any more.

What would happen if you were the only person left who spoke your language? Sometimes a language disappears immediately when the last person speaking it dies. Or, a local language might disappear more slowly.(19)This happens when an official language is getting used less often and children stop learning the local language of their parents.
    Throughout history, the language spoken by a powerful group spreads across a civilization.(20)The more powerful culture rarely respects the languages and cultures of smaller ethnic groups. So, smaller cultures lose their local language as the language of the culture in power becomes stronger.
    The Internet could be thought of as a new method of language control. The United Nations cultural organization, UNESCO, says that ninety percent of the world’s languages are not represented on the Internet.
     (21)Experts say protecting languages is very important for many reasons. Languages contain the histories, ideas and knowledge of a culture. Languages also include valuable information about local medicines, plants and animals.
    David Harrison and Gregory Anderson heading Living Tongues say that many endangered languages are spoken in native cultures in close contact with the natural world. Their ancient languages contain a great deal of information about environmental systems and species of plants and animals that are unknown to scientists. Experts say bringing back threatened languages is not easy, but it is very important work.
19. In what cases would a language disappear?
20. How is culture related to language?
21. Why is protecting languages very important according to experts?