These are words which may not be seen again in a lifetime of reading.

这些词也许今后一辈子也不会再读到了。

《新英汉大辞典》

All jazz lovers should come to the Montreal International Jazz Festival at least once in a lifetime.

所有的爵士爱好者一生中都应该至少来一次蒙特利尔国际爵士音乐节。

youdao

An opportunity like this comes once in a lifetime.

像这样的机会一生也许只会遇到一次。

《牛津词典》

She says the work is a poem about the people who cross our paths in a lifetime.

VOA: special.2010.07.12

So we may live, in your lifetime, to a time when this burden of Southern history may get all but lifted altogether from Southerners, unless we don't forget the Civil War.

也许我们,在有生之年,不会看到这段历史给南方造成的阴影,完全消散,除非我们将内战遗忘

耶鲁公开课 - 美国内战与重建课程节选

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

The worst downturn in a lifetime appears to be over, at least as far as China is concerned.

FORBES: Recovery In China? Not So Fast

Both called it a "once in a lifetime experience" for the fans planning to come.

WSJ: Going to the Bronx��Not the Beach

Suzy Buttress, of Basingstoke, described witnessing the bright light as a "once in a lifetime thing".

BBC: Meteor spotted in night sky in England and Wales