Presheaf
预层
🗣️ 情景例句
My vacation was too short, I needed more time.
假期太短了，再有几天就好了。
If you hadn't slipped and fallen,you wouldn't have broken your leg.
如果你没滑倒,你就不会断腿了。
I simply don't know. He may have plans, but he hasn't yet spoken to me about them.
我一点儿都不知道。他也许有计划，但他还没跟我谈他的想法呢。