The sad news of her father's death was the only cloud on an otherwise happy year.

她父亲的死讯是她愉快的一年中唯一伤心的事。

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The only dark cloud on the horizon was that they might have to move house.

唯一的忧虑是他们可能要搬家。

《牛津词典》

The experiment on cloud formation also seems likely to undermine the particle physics laboratory's reputation for pursuing only blue skies research.

微粒物理实验室一直以研究晴空而著称，如今关于云层形成的实验似乎与它的这一名声背道而驰。

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But a prospective Conservative government is not the only cloud on its horizon.

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The funding shortfall is "the only cloud on our horizon, " she says.

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Unfortunately, the job market was not the only cloud on the horizon.

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