Which of the following statements is true?
a. the first vaccine was developed for cowpox.
b. before jenner's vaccine, there was no prevention for smallpox.
c. travelers to other countries are often required to get special vaccinations. d. missed immunizations cannot be given at future doctor visits.

How do i know when i have a stress headache? what are the symptoms?

During the past few weeks or months, have you noticed any exercises that have become too easy for you? do you think you need to increase the intensity in any of the three exercise areas in your workouts? evaluate your exercise progress in the three exercise areas (cardiovascular, resistance, and flexibility) and list what modifications, if any, you may need to make in your exercise routine.

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.