真的切開：看得見裡面的那一面
核心畫面本來的樣子：刀是真的，切面也是真的。
noun · B2
A cut made straight through something so that you can see what is inside, the flat face that this cut makes, or a drawing of it.
橫切面
核心畫面
Think of a knife going straight across something and stopping there. What matters is not the piece you took off — it is the flat face now showing. From outside you saw only skin; one cut across, and every layer inside is visible at once, side by side.
可以想成一把刀橫著切過去，然後停在那裡。重點不是切下來的那一塊。重點是現在露出來的那一面。從外面看，你只看得到表皮。…更多收起
可以想成一把刀橫著切過去，然後停在那裡。重點不是切下來的那一塊。重點是現在露出來的那一面。從外面看，你只看得到表皮。橫著切一刀，裡面每一層就同時攤在你眼前，一層挨著一層。這個「一刀下去、每一層都看得到」的畫面，就是 cross-section 兩個意思共用的那根線。Two branches
抽一群人：每一層都切到
同一刀改切在一群人身上，切到的每一層就是每一種人。
noun · B2
A smaller group of people or things that shows what the whole, much bigger group is like, because all the different kinds in it are included.
具代表性的一群