我在公园散步时偶然遇到了一位老朋友。

I ___bumped ___into an old friend while I was walking in the park.

他在超市意外遇到他的前任老师时非常震惊。

He was shocked to ___bump ___into his former teacher at the supermarket.

偶然遇到多年未见的人总是一个愉快的惊喜。

It's always a pleasant surprise to ___bump ___into someone you haven't seen for years.