Influenza type a viruses can cause severe illness and are responsible for influenze human pandemics. What is one evolutionary mechanism that could explain why we need a new influenza a virus vaccine every year?

Match the limiting factor with the correct definition. 1. learning about the benefits of exercise location/access 2. problem that can be solved by choosing free activities understanding 3. living close to a park motivation 4. how you were raised money 5. how you feel about yourself and your ability to exercise family behaviors