What are 3 ways boundaries interact?

What factors led to europe's global dominance in economic and political factors? what impacts did that dominance have on other peoples and environments?

What is the difference between emigrate and immigrate? ?

Which revelation resulted from the observation of the spectrum of different galaxies? a. there were more galaxies whose spectrum was blueshifted b. there were no galaxies whose spectrum was redshifted c. there were more galaxies whose spectrum was redshifted d. there were no galaxies whose spectrum was blueshifted