What was the impact of perestroika and glasnost on the Cold War? 1. They strengthened the communist system in Eastern Europe.

2. They brought an end to the strategic arms race between the United States and Soviet Union.

3. They helped lead to the collapse of communist regimes in Eastern Europe

4. They led to the SALT I and II agreements.

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.