What elements would you bring to Mars?

I have a project in science and we're going to Mars. So, one questions asks me which elements I would bring to Mars and why. I am building a closed habitat with oxygen in Mars with wind turbines (for energy), animals, rooms for the astronauts, rooms for recycling water and waste, a recreation room and a room for exercise to keep bones strong. So what elements would I bring? I am thinking oxygen, hydrogen... etc.