盘点生活中的一切，你只有一次机会！

Pack all there is into your life; you only pass this way once!

youdao

我们的孩子只有一次机会得到良好的教育。

Our kids only get one shot at a decent education.

youdao

又不是一辈子只有一次机会考试得好成绩。

It's not the only chance in life to do well on a test.

youdao

There we go. Now if I do this, an infinite number of times, we should get roughly 50/50, but now we have the ability to do things only once in awhile.

开始，如果我们，不停地按这个按钮，我们大致会有一半的机会听到猫叫，但是我们每次只有一次按按钮的机会。

哈佛公开课 - 计算机科学课程节选

And then other people are really excited because it's a once-in-a-lifetime opportunity

而另外一些人真的很兴奋，因为这是一个一生只有一次的机会，

正准备奥运会 - SpeakingMax英语口语达人