Language is the experimental material of language science. Endangered languages contain rare linguistic features, and the content for language research is profound and rich. Since our history of language research is very short, and our understanding of language is still very superficial, every kind of The disappearance of language will take away the linguistic information, make us lose an opportunity to understand the nature of language, and lose a sample of research, which means that it will be more difficult for us to understand the true meaning of language. What's the point of this text? ['Language is the research material of language science.', 'Endangered languages contain rich linguistic features.', 'The disappearance of endangered languages will be an irreparable loss of language science research.', 'Go all out to save endangered languages.']