gǔ / rén / cháng / yòng / yín / qián / jìn / xíng / jiāo / yì / ， / nà / shí / hòu / yín / zi / shì / hěn / guì / zhòng / de / huò / bì / 。

古人常用银钱进行交易，那时候银子是很贵重的货币。

Ancient people commonly used silver money for transactions; at that time, silver was a very valuable currency.