Match each item to the time it best represents. 1. humans began using stone tools
Industrial Revolution
2. birth rates declined, and the average life expectancy increased
1999
3. the world population totaled six billion people
Paleolithic Era
4. the annual population growth rate reached its peak
late 1960s

Which of these statements describes a long-term impact of european imperialism in africa? a. african countries joined together to present a united front against imperialism. b. europeans paid african countries after colonizing them, offering these new countries a fresh start. c. european powers drew the current borders, splitting ethnic groups among modern countries. d. africans became more loyal to their countries than to their ethnic groups.