Which of the following kingdoms was the first to take control of the salt trade? A. Mali
B. Ghana
C. Egypt
D. Songhai
Please select the best answer from the choices provided

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