The oxygen content in the atmosphere of the early earth is thought to have increased significantly once which of these developed? f photosynthetic bacteria g amino acids h mitochondria j archaebacteria

and after water is usually warmed by the sun the water temperature raises and then evaporates .

the elements of art are the visual tools that the artist uses to create a composition. these are line, shape, color, value, form, texture, and space.

the principles of art and design are balance, contrast, emphasis, movement, pattern, rhythm, and unity/variety.