He is unpredictable, weeping one moment, laughing the next.

他令人难以捉摸，一会儿哭，一会儿笑。

《柯林斯英汉双解大词典》

One moment.

马上好。

youdao

youdao

She hoped that for just one moment she could satisfy her husband's highest ideals.

VOA: special.2009.09.26

You may feel one emotion at one moment, different emotion the next. That's Ok.

你可能先体会到一种情绪，然后又体会到另一种，这没关系。

哈佛公开课 - 幸福课课程节选

And the butterfly does appear in just one moment, and it's during the tennis scene. As Humbert and Lolita play, there is one butterfly that flits between them. It's a mark of their equality as artists in that moment.

那蝴蝶曾经在短短的一瞬出现过，那是,在那个打网球的场景里，当亨伯特和洛丽塔打球的时候，一只,蝴蝶从他们中间飞过，它标志着他们在那个时刻是艺术家。

耶鲁公开课 - 1945年后的美国小说课程节选

There is always one moment in childhood when the door opens and lets the future in.

FORBES: Thoughts on Children

But one moment of courage, idealism, and bipartisan unity can change American history forever.

CNN: State of the Union Address

In any of those places that I covered, it just takes one moment to be unlucky.

BBC: Tales from the frontline