So much of our life again if it is all in control, what happens when something doesn't go the way we have planned.

如果我们的生命总是风平浪静，一旦事情与我们计划的不同,我们该怎么办。

普林斯顿公开课 - 人性课程节选

And once you know how it sounds, making those sounds for yourself would be a lot easier to do.

一旦你知道该怎么发音，你就能更加容易地把它说出来。

想征服英语的话 - SpeakingMax英语口语达人

Once you got this, you realize what you got to do.

一旦写出了这两个式子,你就知道该怎么计算了

耶鲁公开课 - 基础物理课程节选