他在黑暗的走廊里绊了一跤。

He ___stumbled in the dark hallway.

她在回答问题时有点磕磕绊绊。

She ___stumbled a bit when answering the question.

我在整理房间时意外发现了一盒旧唱片。

While cleaning my room, I ___stumbled across a box of old records.