metagreywacke

例句：

1. 1. The mine was producing a lot of metagreywacke.
   矿井正在生产大量的元灰色岩屑。
2. 2.The engineer used the metagreywacke to build the bridge.
   工程师使用元灰色岩屑来建造这座桥。
3. 3.The mining company is concerned about the environmental impact of metagreywacke.
   矿业公司对元灰色岩屑的环境影响表示关切。