Please help!

Professor Snape has just finished creating a new textbook entitled "Particular Peculiar Potions" and has sought your advice. 1. What 2 things does he need to show in order to prove his work is protected by a copyright? 2. Once the work is copyrighted, for how long will it last? 3. Once the work is copyrighted, Snape discovers that a few of his students have created their own textbook called "Particularly Pointless Potions" in which they use humor and poke fun at the recipes in Snape's book. Snape is none-too-pleased by this discovery - can he prevent his students from publishing their work? Why or why not