在回家的路上，我意外地遇到了我的高中老师。

On my way home, I ___encountered my high school teacher unexpectedly.

她在新的工作岗位上遇到了很多挑战。

She ___encountered many challenges in her new job position.

我在公园散步时意外遇到了一位老同学。

While walking in the park, I ___encountered an old classmate by chance.