Imagine a washtub about half full of water. A toy boat containing a rock floats in the water. Imagine that you lift the rock out of the toy boat and set it aside (NOT in the tub). Would the water level in the tub become higher or lower or would it remain the same as it was when the rock was in the boat?

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.