老师一走进教室，所有学生都站了起来。

All the students ___stood up when the teacher entered the classroom.

他的借口在追问下没能站得住脚。

His excuse didn't ___stand up when questioned further.

我们约好八点看电影，但她放我鸽子了。

We agreed to meet at 8 for the movie, but she ___stood me up.