What is the most important part in the respiratory system?

The lungs.

The lungs are paired, cone-shaped organs which take up most of the space in our chests, along with the heart. Their role is to take oxygen into the body, which we need for our cells to live and function properly, and to help us get rid of carbon dioxide, which is a waste product.

I’m sorry I do not know what the answer is. Are you in forensic science? I’m making my 4 year plan, and I put that as one of science classes. If you are in that high school class can you provide any details on that class. If you know the answer to their question and the second spot is full, please comment under my question for them.