The diagram/graph below is called a .  The letter A indica…

  The diagram/graph below is called a .  The letter A indicates the .  The letter B indicates the .  The line marked with the letter A is based on .  What conclusion is drawn from our understanding of this diagram, in other words what is the implication of these data . 

The structure of a spiral galaxy includes; spiral arms, a ce…

The structure of a spiral galaxy includes; spiral arms, a central bulge and .  The motion of stars in the spiral arms is .  The motion of stars in the central bulge is .  The Sun is of the Milky Way galaxy.  When viewed perpendicular (at right angles) to the plane of the spiral galaxy the dark patches are .