Epidemiology is defined as the study of:
where and when a disease occurs, and how it is transmitted.
when a disease occurs.
how a disease is transmitted.
where a disease occurs.

Need 5. reflection what factors did you use to determine the validity of your sources? (what was most important and guided your decision to determine validity? ) what factors did you use to determine the reliability of your sources? what was the most important and guided your decision to determine reliability? what form of media resources (internet, publications, music, advertisements, video, etc.) do you think were the most valid and reliable for your question? support your answer. what was your best source? support your answer.