Translation of cascade in Spanish

I would like to give you a proofreader's project. Proof reading sample sentences that were entered into the dictionary by our users. It is a very tough project and needs a lot of discipline and patience.
I looked at your site on the Internet. It is very beautiful, the graphics are interesting and the site leaves a clean impression. I think that paintings and art in general are very interesting.
Three years ago I was with my friends in South Korea whom I met in my English class in Washington. Then I was in America for another three years, one in Oklahoma and two in Alabama.