mining by stages

例句：

1. 1. The company has adopted a miningby stages approach to reduce environmental impacts.
   该公司采用了分阶段开采的方法来减少环境影响。
2. 2. The project is designed to mine bystages, starting with the most accessible areasfirst.
   该项目设计为分阶段开采，首先从最易到达的区域开始。
3. 3. The miningcompany has been criticized for its unsustainable mining practices, which areoften staged over several years.
   该矿业公司因其不可持续的开采实践而受到批评，这些实践往往是分几年进行的。