In earth's is the up and down movements of plastic-like material within that layer.
a. conduction; crust
b. convection; crust
c. conduction; mantle
d. convection; mantle

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.