copper cash

例句：

1. 1. The ancient civilization used copper cash to conduct trade.
   古代文明使用铜币进行贸易。
2. 2. He was rich from his copper cash investments.
   他的铜币投资让他变得富有。
3. 3. Copper cash is a symbol of wealth and prestige in many cultures.
   在许多文化中，铜币是财富和地位的象征。