I'd be grateful if you would keep it a secret.

你如果能对此保密，我将不胜感激。

《牛津词典》

If we try to keep it a secret, she's guaranteed to find out.

如果我们试图保密，她肯定会发现。

《牛津词典》

They had advised us to keep it a secret, but we wanted it out in the open.

他们曾建议我们对其保密，但我们却想将它公之于众。

《柯林斯英汉双解大词典》

How long can she keep it a secret,anyway? Jennifer Lopez gave birth to twins a couple of years ago and drew on her own experiences to play Zoe.

VOA: standard.2010.04.30

I promised Sarah that I was going to keep it a secret.

我答应Sarah我会严守秘密的。

I can't 实战 - SpeakingMax英语口语达人

Hey, I can keep a secret. (LAUGHS) Really, it's just like an old scary story.

VOA: standard.other

As for the third and fourth chapters, Dallas prefers to keep it a secret for now.

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If they were going to announce this in, say, a hotel meeting room, there would be no reason to keep it a secret.

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