TLS Online TPP Program

#Question id: 12038


If you put the following events in the order they occur in the human digestive system, the third event in the series would be:

#Unit 7. System Physiology – Animal
  1. Cells in gastric pits secrete protons.
  2. Pepsin activates pepsinogen.
  3. HCl activates pepsinogen.
  4. Partially digested food enters the small intestine.