impervious subsoil

例句：

1. 1. The construction of the new road will require the excavation of impervious subsoil.
   修建新路需要挖掘不透水下层土壤。
2. 2.The engineers found that the soil was impervious to water, which made it difficult for them to dig.
   工程师发现土壤对水是不透的，这使得他们很难挖土。
3. 3. The farmers used to rely on the impervious subsoil for their irrigation system.
   农民过去依赖不透水下层土壤进行灌溉系统。