What did Hitler do that caused World Was 2? A. He tried to buy back the land Germany lost. B. He attacked the British and the Americans.
C. He invaded Austria an Poland
D. He invaded North Africa

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.