Oxygen first then carbon dioxide follows

8 4 8

This Is a Certified Answer

Certified answers contain reliable, trustworthy information vouched for by a hand-picked team of experts. Brainly has millions of high quality answers, all of them carefully moderated by our most trusted community members, but certified answers are the finest of the finest.
When we inhale the oxygen enters our respiratory system and the circulatory system transport it to different parts of our body (and every cells),when the oxygenated blood is transported it becomes deoxygenated (carries carbon dioxide) and it returns to the heart and lungs and we exhale it.
13 4 13