This diagram is a representation of the_ cycle.

The freezing and boiling point of a substance changes as the air pressure around it changes. for example, at a lower air pressure (higher altitude) it is easier for water molecules to escape from liquid into the air. in a high altitude city such as denver, colorado compared to a sea-level city such as houston, texas, water

It is really hard for me right know

What component of earth’s atmosphere exists entirely as a result of photosynthesis?