Under the Land Ordinance of 1785, what had to happen before public lands could be sold? They had to be free of American Indians.
They had to be surveyed and divided.
They had to be free of enslaved people.
They had to have a school established.

During the paleolithic, hominins grouped together in small societies such as bands, and subsisted by gathering  plants  and fishing, hunting or scavenging wild  animals. the paleolithic is characterized by the use of knapped stone tools, although at the time humans also used  wood  and bone tools.

Clean air provides nitrogen