Unknowns
n. 未知事件（unknown的复数）
🗣️ 情景例句
We rely on the Earth for everyting we need to survive, so let's take care of it.
我们依赖地球获取我们生存的一切东西，因此让我们来细心呵护它。
A good horse often needs a good spur.
好马常要好靴刺。
It's hard to say.
难说。