Fima
费马(已裂变原子数与初始的总装料金属原子数之比)
🗣️ 情景例句
You'll never guess what happened the other day!
你永远也猜不到前几天发生什么事了！
What time does the plane take off?
飞机何时起飞呢？
I'm very sorry, but I can't come.
但很抱歉，我不能来。