我偶然发现一个男孩在街上做着漂亮的卡片。

I accidentally found a boy was making beautiful cards in the street.

youdao

今天早上我偶然遇到了一位来自印度的交换生。

I had a chance encounter with an exchanged student from India this morning.

youdao

我偶然发现睡在桥下的孩子。

I came across children sleeping under bridges.

《牛津词典》

No, I got into philosophy more or less by accident only when I was already at the university.

我接触到哲学，多多少少是因为偶然,那时我已经在上大学了。

普林斯顿公开课 - 人性课程节选

So, if you by chance, I know it's very rare, but if by chance you don't get the class you can always follow up later.

如果你们偶然，我知道不太可能，但是如果不小心你们错过了某节课,你们就可以在之后补回来了。

麻省理工公开课 - 固态化学导论课程节选

I just happened, while I was a graduate student at Oxford University, to meet somebody who is vegetarian and start talking to him about the way we treat animals which I really didn't know much about.

那时我还在牛津攻读硕士研究生,偶然遇到了一个素食者,我们聊到人类是怎样对待动物的,当时我的确不是很了解。

普林斯顿公开课 - 人性课程节选