Bilbo doesn't kill Gollum when he has the chance because he thinks he might need him later on.

he feels sorry for Gollum.

he remembers something Gandalf said.

dependent clause!

example: "before the food gets cold"

now im going to write the whole thing of ru bc i feel like u should lern it on ur own but i would choose allan poe bc allan poe was the main character and the author gives more supporting details on the character.