A dark cloud of bees comes swarming out of the hive.

黑压压的一大群蜜蜂从那座蜂巢涌过来。

《柯林斯英汉双解大词典》

A dark cloud passed over the sky.

一朵乌云从天上掠过。

《新英汉大辞典》

All this is a dark cloud on an otherwise bright horizon for the global economy.

就其他方面而言全球经济正处于美好的地平线，这一切却是飘于其上的乌云。

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In the aftermath of all of the buzz based on the breaking of records, a dark cloud arose.

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Yet a dark cloud hangs over these discussions: the thought of what could have been if things went differently.

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"Today's verdict lifts a dark cloud that has been over me for the past two years, " he said in a statement.

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