By high school, roughly ____ of U.S. adolescents have had a romantic relationship within the ...

By high school, roughly ____ of U.S. adolescents have had a romantic relationship within the previous 18 months.
 
  a. one-quarter
  b. one-half
  c. two-thirds
  d. three-quarters

Question 2

By the year 2040, China expects to have over ______ people over the age of 60 living in that country.
 
  a. 75 million
  b. 150 million
   c. 225 million
   d. 300 million

Question 3

In about ____ percent of families, the relationship between an adolescent and his/her parents is marked by serious conflict and behavioral problems. These issues often predate adolescence and, as children, there may have been problematic relationships with peers.
 
  a. 15
  b. 25
  c. 30
  d. 35

Question 4

What is the primary reason there have been rapid increases in the number of older adults internationally?
 
  a. Because of the declining birth rate.
  b. Because of increased government funds available for pension programs.
  c. Because more adults must work until the age of 75 before being eligible for retirement.
   d. Because of improved health care standards.