Once seen, never forgotten.

一见不忘。

youdao

He was once seen to come out of the place.

有一次有人瞅见他从这里走出来。

《新英汉大辞典》

The first man who came in was a large officer she had once seen talking to her father.

第一个进来的是一个大个子军官，她曾见过他和她父亲说话。

youdao

If you look at the world of Mycenae once again, we've already seen this, you have a despotism of some kind.

如果你重温一下迈锡尼,我们之前也讲过,你会从某种程度上想到专制

耶鲁公开课 - 古希腊历史简介课程节选

See, to be honest even though it might feel like a whole of new stuff at once, it's a pretty small language and so we've almost seen all of the syntactic features thus far so now we'll be able to start focusing more on concepts.

瞧，即使它感觉好像一个新的东西,它是一种相当小的语言,我们迄今看到的几乎所有的语法特征,现在我们将把重点放在概念上。

哈佛公开课 - 计算机科学课程节选

Once an invention is seen to work it is rapidly copied around the world.

而当一种创新品运行顺畅的时候,就会在世界范围内被模仿

耶鲁公开课 - 金融市场课程节选

It was once seen as a Scarlet Letter to have your movie go straight to DVD.

FORBES: The Improving Economics of Independent Film

McKinley, into a destination that was once seen mostly by a trickle of sinewy backpackers.

FORBES

Genentech's Avastin was once seen as one of the most promising cancer fighters around.

FORBES: Why Cancer Drugs Need Genetic Testing