impervious rock

• 不透水岩石,不透水岩

impervious rock的用法和样例：

例句

1. There are also vast numbers of shells in the sedimentary rock and littering the cave floor, some of which may be part or middles-the garbage refuse of prehistoric cave dwellers.
   在水岩石中还有很多贝类和树叶等残留物在洞穴的地面，那些部分是中世纪时居民入住洞穴的残留物。