#1, they remain outside the target cell. #2, bind to the receptors inside the target cell. #3, they have no target cells. #4, are made of proteins.
A condition in which real or imagined fears are difficult to control is called Anxiety disorder.
Being Exposed to Radiation. Also, being exposed to harmful Toxins.
D. Hygiene education
The outbreak of influenza caused many hospitals to post articles about how to avoid the flu and they have recommended to minimize the contact with influenza by taking of your hygiene and staying away from family members/friends with the sickness.
