Her baby starts to fret as soon as she goes out of the room.

她一走出房间，婴儿就躁动起来。

《牛津词典》

If it's out of your control, why fret about it?

如果某件事你控制不了，那为什么还要为它而烦恼呢？

youdao

We dwell on intrusive memories of the past or fret about what may or may not happen in the future.

我们的注意力集中在闯进来的对过去的记忆或者为将来可能会或可能不会发生的事而烦恼。

youdao

Plenty of Americans fret about moral decline, youth violence and the rest of it, but their concerns hardly add up to an encompassing fear for the future.

ECONOMIST: Lexington

Anyway, most of them fret more about improving clearing and settlement in Europe, which is much more expensive than in America and so offers greater scope for savings.

ECONOMIST: Securities exchanges

Such facts do little to mollify critics of supermarkets, who fret that what is at stake is the shape of Britain for generations to come.

ECONOMIST: Supermarket competition