Dr. Nebinger is discussing population trends and their changes with her students. "As you can see looking at these graphics," she says, "in _____ the population of the United States looked most like a pyramid."

What are some of the disadvantages associated with longitudinal studies?

What will be an ideal response?

Teenage pregnancies are a far greater problem today than several decades ago because

A) most public schools teach abstinence only, which does little to prepare teens for safe sex. B) the stigma of teenage parenthood is much worse and many couples refuse to adopt the baby of a teenage mother. C) adolescents are far less likely to marry before childbirth, increasing the negative consequences for both mother and baby. D) most adolescents lack the knowledge and resources to protect themselves from unwanted pregnancies.