Identifying similar words, linguists have come up with what they call an Indo-European parent language, spoken until 3500 to 2000 B. C. These people had common words for snow, beech, bee and wolf but no word for sea.

• 语言学家鉴定了相似文字，发现他们所称的印欧母语一直使用到公元前3500至2000年。讲这种印欧语的人有表示“雪”、“山毛榉”、“蜜蜂”和“狼”的常用词，但没有表示“海”的词。