[Solved] Various strains of E. coli A) may cause disease. B) may be harmless. C) are all exactly the same. D) are all very different from one another. E) may cause disease AND may be harmless. Illegal Behavior: Actions or activities that are prohibited by law, ranging from minor offenses to serious crimes against persons or property. Adolescents: Young people in the transitional stage of physical and psychological development that generally occurs during the period from puberty to legal adulthood. Precocious Puberty: The onset of puberty occurring at an unusually early age, often defined as before 8 in girls and before 9 in boys. Sexual Activity: Behaviors associated with the expression of sexuality and erotic desire, including intercourse and other forms of physical intimacy between individuals.