There's only one event that can bring this many campers together at one time.

VOA: standard.2010.07.31

This is not an one-time event.

这并非一件一劳永逸的事情。

普林斯顿公开课 - 人性课程节选

This is not an one-time event.

这并非一件一劳永逸的事情。

普林斯顿公开课 - 人性课程节选