During the twentieth century, what was one reason that child care centers were created? a. the government mandated that centers opened. b. parents didn't want to care for children as much. c. women began to work during world war i and world war ii. d. there was an increased number of orphans.

The controlled use of fire by hominids: (a) limited the expansion of hominids into certain environments, such as dry grasslands. (b) decreased the amount of food energy available in the hominid diet. (c) contributed to geographical expansion and food production techniques in positive ways. (d) has been shown to contribute little to the digestive process of hominids.