When boys go through puberty their voices change and they start to grow hair on different area of their body such as their chest, face and pubic area. Also they will start to get acne
Because the cells can only use energy in form of ATP.
Its like you can't run a diesel truck on petrol.
Answer:
An ecosytem
Explanation:
I am pretty sure this is right since I just took bio couple of weeks ago. :)