Evolvent
渐开线, 切展线
🗣️ 情景例句
Hold Gerald's hand, please. Great!
请握住Gerald的手。很好！
Some persons do first, think afterwards, and then repent for ever.
有些人做了再思考，从而悔恨终身。
so she went to fetch the porter from his basement.
于是她到地下室去找看门的人。