Across
- 7. splits airways
- 8. trade for oxygen to carbondioxide
- 9. keeps cells alive
- 10. smallest blood vessel
- 12. inhales
Down
- 1. connects it to aveoli
- 2. toxic to humans good for plants
- 3. inflates and deflates lungs
- 4. Tube to lungs
- 5. protects lung
- 6. change in concentration
- 11. collects air