Question

When birds inhale, air enters sacs around the lungs. When air is exhaled, it travels in tubes called alveoli through the lung. This shows how the _________ system of birds works.digestivenervousrespiratoryreproductivecirculatory

Answer 1

The correct option is respiratory

The respiratory system is:

-the network of organs and tissues that help you breathe

-it includes your airways, lungs and blood vessels