The only dark cloudonthehorizon 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》
2
Perhaps the blackest cloudonthehorizon is the threat of climate change.
最令人坐立不安的也许是气候变化带来的的阴霾。
3
At that moment, I'm awe-struck by the power of the season changing from winter to spring, and I realize the spectacle would not be as beautiful without the dark gray cloudonthehorizon.