When a person is running in a 5k race and their body is using the oxygen-energy system to extract energy, from which source(s) can energy be produced?

a. fat

b. protein

c. glucose

d. both fat and glucose?

D

Explanation:

fat is what you burn when working out and glucose is a sugar type materiel so its both of them i think✔

brain development. a child's brain undergoes an amazing period of development from birth to three—producing more than a million neural connections each second. the development of the brain is influenced by many factors, including a child's relationships, experiences and environment.

explanation:

b) the inside picture would look at a very high temperature in a very low ph