Linguistics 语言学 Phen. --- common E.g. Greek. Latin....in common Reasons: Happen by chance Borrowed Same source lang. Discovery Proto-Indo European. Defi. Represent --- Family tree model Compare: real family tree (expl.) What is FTM Mother lang. Daug. lang. Sister lang. Ad (Convenient) Develop. Of lang. Family. Show how close Disad. Too simplified Variations ----e.g. Spanish Evolve --- overnight 词汇： Correspond to Genetically related Reconstructed Trace their ancestry back to Diagram Branch off Do justice to ... Variation 本文来源：https://www.wddqw.com/doc/3106fcd6aef8941ea76e052a.html