1. Humans breathe through which of the following systems?

2. Which of the following substances do we breathe in?

3. Which specific complex molecule do we get from eating?

4. Which of the following expands our lungs during the breathing process?

5. What are the tiny air sacks at the ends of the bronchi called?

6. Where is oxygen stored in our bodies?

7. Which of the following substances do we breathe out?

8. True or False: Our nose helps cool down air prior to getting to our lungs.

9. What happens when we exercise?

10. True or False: We couldn't talk without air.