The pre-teen years occur during the juvenile <span>stage, from 9 to 11 years of age.</span>
Immune system that is the answer to you question I think
They are typically composed of thousands of atoms or more. The most common macromolecules in biochemistry are biopolymers nucleic acids, proteins, carbohydrates and lipids and large non-polymeric molecules such as lipids and macrocycles
Sugar, water, and other food molecules.
