coal screenings

例句：

1. 1. The coal screenings are usedto remove impurities from the coalbefore it is burned.
   煤炭筛选用于在煤炭燃烧前去除杂质。
2. 2. Thecoal screenings process involvesusing a machine to separate differenttypes of coal.
   煤炭筛选过程涉及使用机器将不同类型的煤炭分离出来。
3. 3. Thecoal screenings plant is responsible for cleaningand processing the coal before it is shippedto other countries.
   煤炭筛选厂负责清理和加工煤炭，然后将其运送到其他国家。