calcareous grit

例句：

1. 1. The riverbed is covered in a layer of calcareous grit.
   河床覆盖着一层石灰石砂砾。
2. 2.The engineer used calcareous grit to improve the quality of the concrete.
   工程师使用石灰石砂砾来提高混凝土的质量。
3. 3.The construction crew was tasked with removing the calcareous grit from the site.
   施工团队被指派去清理现场的石灰石砂砾。