Presheaf
预层
🗣️ 情景例句
Unless in uniform, he doesn't look like a policeman.
除非穿上制服，要不他看起来不像警察。
I meet the boy whose aunt is a clerk.
我遇到那个男孩的姑妈是店员。
No, not exactly. But later, peole developed a way of printing, using rocks.
不完全是这样。但后来，人们利用石头，研制了一种印刷方法。