Which description of the term caliph is correct?
a.
the high turret that sits atop a mosque
b.
a follower of abu bakr as muhammad's rightful successor
c.
one of the five pillars of islam
d.
a muslim ruler in the islamic empire

Which of these would be most useful in studying the effect of germs exchanged between the new and old worlds? a. a graph showing the number of europeans between 1492 and 1600. b. a graph showing the number of native americans between 1492 and 1600. c. a primary source description of the symptoms of an unknown disease affecting native americans in 1492. o d. a primary source description of the symptoms of an unknown disease affecting europeans in 1492.