你能在明天的会议上替我一下吗？

Could you ___stand ___in for me at tomorrow's meeting?

主演生病了，所以她的替补演员不得不顶替上场。

The lead actor got sick, so her understudy had to ___stand ___in.

教授被临时叫走了，所以一位同事同意代为授课。

The professor was unexpectedly called away, so a colleague agreed to ___stand ___in and deliver the lecture.