乌云密布

The morning began fine, but now clouds are banking up.

早晨开始晴天, 可乌云密布。

The sky clouded over before the storm.

暴来临前, 天空乌云密布。

The sky clouded over; we could see there was going to be rainstorm.

"天空乌云密布,我们看得出快来暴了。"

The sky blackened and soon it began to rain.

天空乌云密布, 很快便起来。

The thick clouds passed overhead, but fortunately the rain kept off the whole day.

虽然乌云密布, 但很幸运地一整天都。