At about what age does a significant loss of visual acuity begin to be measurable for most adults?

Which of the following is a cause of increasing obesity in American children?

A) genetics alone B) environmental factors alone C) obese role models D) a mix of genetics and environmental factors

Which of the following reflects the latest information regarding racial and ethnic differences in the timing of first intercourse?

a) African Americans generally have sex for the first time earlier than do Puerto Ricans, who have sex earlier than whites do. b) There is no significant difference in when racial and ethnic groups have sex for the first time. c) Whites generally have sex for the first time at an earlier age. d) Sex education has made a significant impact on when ethnic and racial groups will have sex for the first time.