Medullation
髓形成, 髓鞘形成
🗣️ 情景例句
I have to sign copies of my book for a lot of people
我还必须为许多人在我的书上签名
What are friends for?
朋友是做什么用的？
he answered me, but he spoke neither slowly nor clearly.
他回答了，但他讲得既不慢也不清楚。