Wich is the method that scientists use to determine the composition of earths layers

Agricultural practices in the united states nearly led to the extinction of the peregrine falcon during the 1950s and 60s.

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 one difference between austria and switzerland? a. austria is landlocked. b. austria has more minerals resources c. austria has a strong tourism industry d. austria has a strong dairy cattle industry