What role do cockroaches play in our ecosystem? What would happen if all of Earth's gases combined? Why is the universe expanding? What is the most flammable gas? Why does the Earth look flat from the ground? How does the brain co-ordinate the body? How were the pyramids built so long ago? What happens to our body during a heart attack? In this 'Classroom Edition' of Ask The Naked Scientists, Dr Chris Smith and are answering the questions set by pupils at John Graham Primary School... Like this podcast? Please help us by supporting the Naked Scientists