What happens when the lungs recoil?
a. ribs and diaphragm muscles contract.
b. internal respiration occurs.
c. inspiration occurs.
d. expiration occurs

the answer is cell division : )

bacteria could be both, harmful and to us. harmful bacteria could make us sick and probably even by getting the chances of getting a disease, but good bacteria fight it off with your immune system. there is always bacteria everywhere we go. we need to make sure to wash our hands after using the restroom, before eating, after eating, after petting an animal too. so you see, bacteria is everywhere and is harmful or . i hope this . : ) : ) : )

garbage disposal because lysosomes dispose of old cell parts like garbage disposals dispose of old food.