zài / méi / yǒu / wén / zì / jì / lù / de / nián / dài / xǔ / duō / zhī / shi / zhǐ / néng / tōng / guò / kǒu / ěr / xiāng / chuán / bǎo / cún / xià / lái

在没有文字记录的年代，许多知识只能通过口耳相传保存下来。

In times without written records, much knowledge could only be preserved through oral transmission.