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》

When the student reached the door, the teacher called out, "One moment, boy, what's your name?"

当学生走到门口时，老师喊道：“等一下，孩子，你叫什么名字？”

youdao

One moment.

马上好。

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