Question

1. your body needs oxygen to survive and the job of your respiratory system is to bring the into your body and remove the from your body.

Explanation:

The respiratory system's main function is gas exchange. It takes in oxygen ($O_2$) which is essential for cellular respiration (to produce energy in the form of ATP). And it expels carbon dioxide ($CO_2$) which is a waste product of cellular respiration.

Answer:

oxygen; carbon dioxide