zài / zhǐ zhāng / pǔ jí / zhī qián / yì xiē / zhòng yào / wén jiàn / huì / xiě zài / yáng pí zhǐ / shàng / bǎo cún

在纸张普及之前，一些重要文件会写在羊皮纸上保存。

Before paper became widespread, some important documents were written on parchment for preservation.