Across
- 2. from where fish breathe
- 6. how many brochioles are in each lungs
- 8. what is another name of trachea
- 9. what is name of clean air
- 10. who exchange center for carbon-di-oxide and oxygen
Down
- 1. which is biggest muscles of body
- 3. who stops when dust particles go inside nose
- 4. which tubes take air inside and out of body
- 5. things use to make energy
- 7. how many organs make make respiratory system