America's indigenous peoples were the first cultivators of what ...

[Lobcity]

America's indigenous peoples were the first cultivators of what percentage of the crops grown in the world today?
 
  a. 10
  b. 30
  c. 60
  d. 80

Question 2

Over the course of our evolutionary history, most environmental stressors were climatic and geographic. Now, however:
 
  a. humans have little environmental stressors, climatic or geographic.
  b. nonhuman primates have more stressors than humans.
  c. humans face a series of new environmental stressors of their own making.
  d. humans also face daily weather stressors.
  e. humans have climatic stress, but geographical stress has been removed because of technology.

[ErinKing]

Answer to Question 1

c

Answer to Question 2

c