Which of the following was a cause of the mexican-american war?

a.
the united states refused to negotiate with mexico.

b.
mexico tried to acquire new mexico.

c.
mexico wanted to expand trade to china.

d.
the united states wanted to acquire san francisco.

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.