( ) to keep people who have a disease away from others A. cooperation 2. ( ) periods of ten years B. quarantine 3. ( ) the plan you use to achieve something C. risk 4. ( ) the injection of medicine to protect from disease D. take steps 5. ( ) the possibility of something bad happening E. vaccination 6. ( ) working with someone to achieve a goal F. decades 7. ( ) find somebody by following information or signs G. track 8. ( ) do a series of actions to achieve something H. strategy