Weightlessness and space flight tend to cause severe motion sickness because these situations affect the __________ system

Relationships with parents affect how adolescents deal with issues of identity. In particular, both younger children and adolescents benefit from parenting

A) that is supportive and accepting. B) that lets youngsters express themselves. C) that provides reasonable expectations and limits for their behavior. D) all of the above

Even though adolescents make up only 25 percent of the population of individuals who are sexually active, they account for ________ of all new cases of STDs each year

A) 30 percent B) 50 percent C) 75 percent D) 90 percent