Some of the fluorite produced from the lead mines was used as backfill underground.铅矿产生的一部分萤石曾被用来作为地下回填材料。Chrysler says it intends to backfill jobs vacated by the buyouts.克赖斯勒汽车公司宣布，在买断之后计划将招聘新的员工填补职位空缺。Dig a large hole for the plant, then backfill with soil and compost.给植物挖一个坑，然后用泥土和肥料回填。