Give tree graphic reasons why cities grew up on rivers

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

Which of the following is a measure of the amount of light a star directly emits? a. luminosity b. wavelength c. brightness d. intensity

If a volcano’s magma is high in silica, the volcano will probably a. erupt quietly. b. remain dormant. c. erupt explosively. d. produce dark-colored lava.