Susan Sills, Age 10, Of Toronto, Ont., Canada, For her question:

Why are rain clouds dark?

Clouds are made of miniature droplets of water separated from each other by plenty of air space. In a frothy white cloud, the droplets axe very tiny. The foamy white is created by sunbeams dancing and prancing with misty droplets and airy spaces.

In a rain cloud, the droplets are big   big enough to shut out the sunbeams and make shadows of their own. Billions of their tiny shadows cast gray and glowering black through the cloud. The white sunlit cloud then becomes a dark rain cloud.