> Once we changes phases, realize that a whole lot more was happening on the next screen.

>一旦我们有所改变，下一秒就会发生许多,翻天覆地的变化。

哈佛公开课 - 计算机科学课程节选

But once the financial crisis hit, things changed a little bit, and so there is more competition.

但一旦金融危机爆发了，情况稍微有所改变，因此竞争就会更激烈了。

哥伦比亚的氛围 - SpeakingMax英语口语达人

It sends it's signal, it's signal - the signal that it sends is this change in voltage, and once it changes, maybe it's all done.

它发出信号,它通过电压的改变发出信号,然而一旦电压改变,细胞的使命到此就终结了

耶鲁公开课 - 生物医学工程探索课程节选

Because once things started moving, it tends to move in that direction.

因为一旦事物开始改变，他们就会有朝这个方向运动的倾向。

麻省理工公开课 - 计算机科学及编程导论课程节选