Which of the following science related statements are observations rather than opinions? select all that apply.

Organisms within a population must compete for resources to survive

Why does bubbling occur when vinegar mixed with baking soda

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