Fill in the Blanks Infectious diseasesOnline version Unhealthy habits: Infectious diseases by Jose Ricardo Desfilis 1 cells rest pathogens contagious spread defences stronger diet mouth colds air Some diseases , such as , are . This means they from person to person through the . The germs or usually enter the body through the nose or the . The body has natural , such as white blood , to protect itself against germs . If you get plenty of , drink enough water , exercise and have a healthy , your defences will be .