Which macromolecule will our bodies use first for energy?

Your body uses carbohydrates, lipids and proteins for energy. When small organic molecules bind together, they form larger molecules called biological macromolecules. Biological macromolecules fall into four categories: carbohydrates, proteins, lipids and nucleic acids. Your body uses carbohydrates, lipids and proteins for energy.

Explanation:

Your body uses carbohydrates, lipids and proteins for energy. When small organic molecules bind together, they form larger molecules called biological macromolecules. Biological macromolecules fall into four categories: carbohydrates, proteins, lipids and nucleic acids. Your body uses carbohydrates, lipids and proteins for energy.

i'd say that the moon rock is about 2.2 billion years old.

a "theory" a suggestion that is not 100 % accurate, or a figure. some people say its a theory because they of all the passed theory's about one subject. it depends sometimes theory might be accurate and sometimes they are.