Irreplaceability
n. 无法调换, 不能取代
🗣️ 情景例句
Make sure you file this invoice straight away; I don't want it being misplaced.
记得现在就把发票给开了，我可不想弄错了。
Think nothing of it.
别放在心上。
You're really killing me!
真是笑死我了！