stumble upon片语动词KK [ˋstʌmbəl əˋpɑn] /ˈstʌmbəl əˈpɑn/发音片语动词1偶然发现、无意中找到I stumbled upon an old photo album while cleaning the attic.我在清理阁楼时偶然发现一本旧相册。2碰巧遇到、偶遇We stumbled upon an old classmate at the train station.我们在火车站碰巧遇到一位老同学。用这个字练口说→