Across
- 2. transport air
- 4. cauliflower shape
- 6. fluid filled
- 8. Breathe
- 9. Pumps
- 11. 2 of them
- 14. tube
- 15. supplier
- 17. thin membrane
- 19. holes
- 20. Cavity
Down
- 1. artery
- 3. covers lungs
- 5. double walled
- 7. 3 lobed
- 10. grouped
- 12. Central
- 13. T cells
- 16. Riged
- 18. bubbles