1) My sister thinks she's intelligent than me, but I don't agree! (intelligent) 2) Avatar is probably (bad) film I’ve seen.
3) Do you think the Harry Potter films are (good) than the books?
4) Who is (powerful) person in your country?
5) John is (nice) person that I know.
PLEASE HELP
1. More intelligent
2. The worst
3. Better
3. The most powerful
5. The nicest