Demarcator
n. 划边界的人；立界物
🗣️ 情景例句
Thank you, sir.
谢谢。
A blate cat makes a proud mouse.
猫儿腼腆，老鼠翻天。
The tape was so stick that they did not dare to cross it.
胶带极粘，蚂蚁不敢从上面爬过。