1.   A dark cloud covered the sun.

2.   A dark cloud descended upon the valley.

3.   A dark cloud floated across the moon.

4.   A mild breeze shook the leaves and a few dark clouds scudded across the sky.

5.   And those bushy eyebrows that resembled dark clouds on his horizon.-How come?

6.   Dark clouds floated across the moon.

7.   Dark clouds gathered overhead.

8.   Dark clouds rolled over denser, thicker clouds and merged with them.

9.   Dark clouds threatened rain.

10.   Dark clouds usually mean rain.