1. annually


2. avoid


3. cause


4. cemetery


5. elderly


6. fever


7. flu


8. frequently


9. guarantee


10. impact


11. infect


12. influenza


13. mild


14. mucous


15. occur


16. particular


17. prevent


18. preventive


19. prolong


20. protect


21. severe


22. shot


23. sneeze


24. sore


25. symptom


26. throat


27. victim


28. virus