II. Fill in the blanks the correct word or term using the box below. air bronchi nose oxygen inhalation respiratory pharynx carbon dioxide trachea exhalation blood lungs to live. 2. is a type of gas that Humans and animals need 1._ enters inside the body. The 3. system is responsible for exchange of oxygen and carbon dioxide inside the body. During 4. we breathe in air and enters in the 5. which is the first organ in the respiratory system. From there, it will pass through the 6. and will travel.down to the start of the lower respiratory tract, 7. The trachea have branches called 8. which lead to the 9. the primary organs of the respiratory system. Oxygen enters the 10. and at the same time, the waste gas 11. leaves the blood and body by 12.​