Why should agreements aimed at preventing or reducing ozone depletion be international?

The oxidizing agent our bodies use to obtain energy from food is oxygen (from the air). if you breathe 15 times a minute (at rest), taking in and exhaling 0.5 l of air with each breath, what volume of air do you breathe each day? air is 21% oxygen by volume. what volume of oxygen do you breathe each day?

What are some possible short and long term medical concerns for crew members on longer space exploration trips

Name the organs of humanelemintary canal.