工人们为建筑项目挖了一个深坑。

The workers dug a deep ___pit for the construction project.

她教社区如何挖堆肥坑来回收有机废物。

She taught the community how to dig compost ___pits to recycle organic waste.

采矿作业后，地面上布满了许多坑洞。

After the mining operation, the landscape was scarred with numerous ___pits.