Say you're some place where people are digging in order to build a road or foundation, and in the wall of their hole, you spot one or more layers of pottery shards, stone implements or shells: That's the cultural stratum.
如果那天你在某處，像正在開馬路或是挖地基的工地附近，看到和地表垂直的斷面上，有一層或多層陶片、石器或貝殼，那就表示你發現了文化層。