Protocambium
原形成层
🗣️ 情景例句
You are twenty-one, a grown-up young lady old enough to make up your own mind.
你已经21岁了，已经到了可以自己做主的年龄了。
Ouch! I fell down and cut my knee!
好痛呦！我跌倒割伤了膝盖！
I'm full, thank you.
我饱了，谢谢你。