What natural features served as the border between china and north korea

What part did glaciers play in forming the great lakes?

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

What is the pattern of urbanisation around the word?