#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.
Substance abuse, also known as drug abuse, is a patterned use of a drug in which the user consumes the substance in amounts or with methods which are harmful to themselves or others, and is a form of substance-related disorder.
It's too early for the baby to get custom to being picked up every time it cries most babys cry when they need attention or the basics gasy hungry or to be changed him touching the baby comforts the baby and this is a stage of development where the bond between parents and infant is made.