I think the answer you are looking for is that the stomach is the fourth level of organization.
Answer:
Can be used for simple experiments at home or in the classroom
A cell or Atom is something that can process life or can processed into an object. (The atom is in objects and life Such as animals and humans as a cells in just humans and animals
The factors that affect personal health that are the most easily controlled are c) lifestyle.
You can easily change the way you are living, whereas these other things cannot be.
