How does the structure of this system complement its. function

Complement is a system of plasma proteins that can be activated directly by pathogens or indirectly by pathogen-bound antibody, leading to a cascade of reactions that occurs on the surface of pathogens and generates active components with various effector functions.

They probably don't understand either 1. what the nightmare is about or 2. his anxiety and stress

Avaccine? hiv preventing, of course.