In addition to heating, cooling, cooking, providing transportation, and fueling engines, what is another major use for our natural resources?

The natural resources acts as the source of food, and they provide raw materials for the production of goods.

Explanation:

The substances obtained from the Earth, which are used to encourage life and meet the needs of the people are known as natural resources. Any natural things, which are used by humans can be known as a natural resource. The natural resources are used to fuel, to make food, and provide raw materials for the generation of goods.  

The food consumed by people comes from natural resources, that is, animals and plants. The natural resources are considered as the raw materials for generating products, which one uses every day.  

fumikage isn't really a bird, and tsuyu does have teeth. tsuyu has a transformation quirk which still allows her to be partially human. otherwise we'd have a large frog running around. fumikage has teeth because again, he isn't a bird. his head was a quirk mixture if i'm correct.