Why are television networks considered part of mainstream media? O A. They show commercials.
B. They have wide audiences.
C. They have been on the air for more than five years.
D. They make profits.

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.