D, Mucous membranes are not within the body, thus they are the first of all the options that would encounter pathogens.
Is it 50%? Since some animals are smart and have some human traits
Answer: The digestive system rids the body of the cells' waste and the excretory system fuels the cells. The digestive system does physical digestion while the excretory system carries out chemical digestion.
Explanation:
