Minerals are naturally occurring inorganic solids that possesses an orderly internal structure and a definite chemical composition. This orderly internal structure or regular pattern is called its A)hardness.
B)cleavage furrow.
C)specific gravity.
D)crystal structure.

Arunner is training for an upcoming marathon by running around a 100-m-diameter circular track at constant speed. let a coordinate system have its origin at the center of the circle with the x-axis pointing east and the y-axis north. the runner starts at (x, y) = (50 m, 0 m) and runs 2.5 times around the track in a clockwise direction.