What do you think are the gases?

Do you know what are alveoli? Do you know what are capillaries?

What is the gases exchanges

I know this is under homework help but we really aren't much of a research tool like Google or othe similar sites. If you are researching, different than asking for outright answers with no work involved, then just Google it. I just had a great read at the Merck Manual site

Also, learn to formulate your questions properly; "What are the gases exchanged?"

What are the gases you think are exchanged?