天上乌云密布，预示就要下雨。

There were dark clouds overhead promising rain.

《牛津词典》

天空乌云密布，阴沉沉的。

The sky was dark and threatening.

《牛津词典》

天空中乌云密布。

The sky was full of dark masses of clouds.

《牛津词典》

天空乌云密布， 电光在云块间闪动。

The sky was overcast, the ligtning leaped from cloud to cloud.

《新英汉大辞典》

一天，乌云密布，突然间便暴雨如注。

One day dark clouds came in, burst open and poured sheets of rain.

youdao

天空乌云密布，很快便下起雨来。

The sky blackened and soon it began to rain.

youdao

天空乌云密布，接着下起雨来。

The cloudy sky was followed by rain.

youdao

虽然乌云密布但飞机还是起飞了。

The clouds were dark, new the airplane took off.

youdao

乌云密布预示着暴风雨将到来。

The heavy black clouds threaten a storm.

youdao

天空乌云密布，看起来要下雨了。

The sky is overcast. It looks like rain.

youdao

突然天气乌云密布，此前毫无征兆。

The clouds had comedown so suddenly we had no warning.

youdao

乌云密布，但太阳最终还是钻出云层。

It was a cloudy day, but the sun at last broke through.

youdao

从窗口望出去，她看到天空乌云密布。

Looking out her window, she noticed the sky had become overcast.

youdao

仅在几个月之前，东欧西部还乌云密布。

ONLY a few months ago a deep gloom hung over the western Balkans.

youdao

我们离港时，天上乌云密布。

Dark clouds tureatened as we put forth from the shore.

youdao

从乌云密布的天可以看出就要下雨了。

It can be seen from the black clouds that there will be raining.

youdao

乌云密布，天空突然暗下来。

The sky became suddenly covered with dark clouds.

youdao

假如今天乌云密布，就借用明天的太阳吧！

Borrow from tomorrow's sun if there are clouds today.

youdao

乌云密布，可能将要下雨。

We probably will get some rain from those dark clouds.

youdao

突然乌云密布，狂风大作。

Suddenly overcast, and such a violent storm arose.

youdao

好像是乌云密布的天空顷刻间阳光四射。

It was as if a dark sky suddenly, turned into sunshine.

youdao

乌云密布，看来会下雨。

The dark clouds promise rain.

youdao

天空突然变得乌云密布。

The sky became suddenly covered with dark clouds.

youdao

天空突然变得乌云密布。

The sky became suddenly covered with dark clouds.

youdao