The important gas named was not present in the early earths atmosphere. Therefore, the first cells to evolve were organisms.

Most of the fossils found in virginia are in the coastal plain, valley, ridge, and appalachian plateau regions, best suggesting that these geographic provinces a) were once covered by seawater. b) are the oldest parts of virginia. c) have a great deal of karst topography. d) have large amounts of sedimentary rock.

Which muscle is responsible for inhalation ?

What are the student's observations and inferences before he starts his investigation?