Definition: used to talk about something that happened in the past Level: A2
有一天，我回家发现窗户被砸碎了。
___One ___day, I came home to find my windows smashed.
有一天，我正在读一本有趣的书，突然有人叫我。
___One ___day, I was reading an interesting book when someone called me.
有一天，他决定学习烹饪。
___One ___day, he decided to learn how to cook.
