乌云的英文：
black clouds

参考例句：

The clouds are building up
乌云正在堆积起来。

The clouds blotted out the moon
乌云遮住了月亮。

During the whole of that day there had been an unusual degree of heat in the air, and the sky was heavy with clouds.
那天整天极为炎热，空中布满乌云。

A watery sunlight shone down through an opening in the fast-moving cloud cover.
一束淡淡的阳光从飞快移动的乌云缝隙间投射下来。

If the clouds break up, we can go for a hike.
如果乌云散开了，那我们就能去徒步旅行了。

Every cloud has a silver lining.—— W. S. Gilbrt
每朵乌云背后都有阳光。——吉伯特

The black clouds concentrated into a dense mass.
乌云密集。

The sky is overspread with black clouds.
天空布满乌云。

Dark clouds were gathering.
乌云正在密集。

Those dark clouds spell rain.
那些乌云意味着下雨。

black是什么意思：
adj. 黑的；黑人的；不加牛奶的；黯淡的；很脏的；阴郁的；邪恶的
n. 黑色；黑人
v.（使）变黑

This is Sergeant Black.
这位是布莱克中士。

It is a black township.
这是一个黑人居住区。

Colour black--Determination of blackness
GB/T7048-1993色素炭黑黑度的测定

In “the black cat”, the adjective “black” modifies the noun “cat”.
在“那只黑猫”中，形容词“黑的”修饰名词“猫”。

A big black bug bit a big black bear.
一个大黑虫咬了一个大黑熊。

clouds是什么意思：
n. 云；云状物；阴影；大群；黑斑
v. 使忧郁，暗淡；以云遮敝，乌云密布；使混乱，不清楚；玷污

Cloud the issues.
混淆争端

There was heavy cloud and a lowering cloud base.
阴云密布，而且云层愈来愈低。

cloud over;(of the sky)become covered with clouds
（指天空）布满了云.

The moon was obscured by the clouds.
月亮被云遮暗了。

To cause to be obscured;cloud.
使模糊；遮挡