Make a bold introduction. If it's something about world wars mention the human nature that we all have.
Ex) Since the beginning of time, humans have battled against snakes, animals and each other for a want or desire...) then continue on with your introduction.
If you were reading a book , what would grab your attention? Would It be funny or intense? is there a fact you didn't know? Is there only one word that grabbed your attention. Ask yourself these questions and hopefully your brain puts you to work!