Answer:
The skin
Digestive tract
Vagina
Mucous membrane
Explanation:
The skin prevents microbes from entering the body
Digestive tract e.g. stomach acid is a natural defence mechanism
The vagina is acidic and this prevents harmful bacteria from growing with it's own flora.
Mucous membranes e.g. lining of the mouth, nose, eyelids are all defense mechanisms.
Likely the chronological age, mainly because it would explain the differences in puberty stages between the two boys, which is an example of physical maturation.
Answer:
true
Explanation:
like your stomache breaks down your food and then it travels to your small and large intestines where it gets broken down even more
