capacity of surfacemine

例句：

1. 1. The surface mine has been closed due to safety concerns.
   由于安全问题，这个露天矿已经关闭了。
2. 2.The mining company is exploring new ways to improve the efficiency of its surface mine operations.
   这家矿业公司正在探索提高其露天矿作业效率的新方法。
3. 3. The surface mine is a significant source of employment in the local economy.
   这个露天矿是当地经济的重要就业来源。