What percentage of North American children have at least one dental cavity by age five years?

Recent brain imaging data indicates that drug dependence is caused by an underlying biological abnormality

Indicate whether the statement is true or false

Martha always has drama in her life. When she has a boyfriend, she is at first head over heels in love. Her boyfriends get tired of her demanding reassurance that they love her just as much. Eventually they do some little thing that she perceives as abandonment. She has even cut on herself to show them how hurt she is. Her moods change often in a day and she is frequently impulsive. Martha best fits the description of which of the following disorders?

a) social anxiety disorder b) borderline personality disorder c) antisocial personality disorder d) schizotypal personality disorder