chance upon

偶然发现, 偶然碰见

例句与用法：

I met her by chance on the way.

我恰巧在路上遇见了她。

Perhaps you might chance on the dictionary at some old bookstall.

或许你会碰巧在旧书摊上买到这本辞典。

The apple fell by chance on his head.

那个苹果意外地落到他的头上。

Won't you take a chance on the prize?

你有意争取奖品吗?

详细释义：

巧遇

We chanced upon him in the park the day before yesterday.

我们前天在公园里碰巧遇到他。