Well there are the obvious ones, life, death, love, desperation (what some people will do to survive), beliefs, and the fact that we spend our whole lives and experiance so much all on a tiny speck in the galaxy, which is an even smaller spec in the vast universe.
Or you could relise that she's probably on to you and thinks that making you contemplate life will make you realise how much of your life you are wasting skipping class when you could be learning skills you may use for the rest of your life, while at the same time, also encouraging you to graduate by saying how smart you are, and how you have so much potential.
But realy, think about WHY.
WHY do we continue to exist.
WHY is there science, religeon, wars, love, freindship, bullying, crime, you name it.
and the one your teacher most probably wants you to think about WHY are you doing this essay.
__________________
|