Which of the following best describes why some great plains tribes needed portable homes? a. they were warrior societies that had to move quickly. b. they traveled to new locations to find better farmland. c. they were nomadic bands following the bison herds. d. they were often attacked by rival tribes.

Children begin to use tools at about what age? a. 18 months b. 2 years c. 1 year d. 6 months

How does specialization enable countries to trade with one another? a country can make and sell goods affordably and buy goods that it is inefficient at making. a country can make what it chooses and sell its goods to other countries. a country can decide to buy everything it needs from other countries. a country can efficiently make goods that were once difficult to make.

What was different about warfare in the early 1800s and early 1900s?