他在不平的路上绊了一下，差点摔倒。

He was ___stumbling on the uneven road and almost fell.

她因为紧张，在面试时说话一直结结巴巴。

She kept ___stumbling through her words during the interview because of nervousness.

我们的旅行计划因意外遭遇签证问题而搁浅了。

Our travel plans ___were derailed when we unexpectedly faced visa issues.