Across
- 3. What enters the lungs when the animal inhales.
- 4. Takes place in the alveoli across a semi permeable membrane.
- 5. Divides the nasal passages into two.
- 6. Follows the trachea and eventually splits into two.
Down
- 1. Where the air first enters the body when the animal inhales.
- 2. The name of the system.