Articles + Copyright + Ownership

Question about the copyright. If I write my own article and I post it on steemit, can some one actually use it, and post it somewhere else? can someone steal my articles, and use it as his own ones? can someone sale my articles? will the history of my articles be deleted when I close my steemit account? can newspapers use my articles, and pay me for it? can I decide, who can use it and can I decide who can buy my articles? Thank you for the infos