The structures that an animal uses to exchange gases with its surroundings make up the

Idon’t understand your question but if u mean the difference in america vs in africa

Whoops my handball aswnsrr later

It may be written down (as in the united states) or it may be unwritten (as in great britain). this is the 1787 meeting at which the  constitution of the united states  was debated and agreed upon. this was a 1787 meeting called by congress to amend the articles of the confederation.