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