How did oxygen first enter Earth's atmosphere? O A. Breakdown of Precambrian rocks O B. Meteorite impacts OC. Volcanic outgassing OD. Biological processes

Lucia is walking barefoot in her yard. she accidentally steps on a nail. how will her nervous system work to generate a reaction? arrange the eventschronologically.

Vaccines are weakened forms of disease causing microorganisms, which are given to patients to prevent disease. after the vaccine is administered, the immune system responds by creating a(n) to recognize the a.) antibody, antibiotic b.) antigen, antibody c.)antibiotic, antibody d.)antibody, antigen

Stephen is a student who wants to test his knowledge of medical terminology. which option could he use?