About how many deaths occur by suicide each year around the world?

In the majority of cases, the cause of mental retardation is ______

a. clearly identified genetic abnormalities b. unknown c. poor prenatal nutrition d. prenatal drug abuse by the mother

Jane and John are married and have three children. Based on current research we can conclude that:

a. the number of children they have will not affect the number of years she spends in the workplace. b. John spends less time with his own children than his father spent with him. c. Both parents spend about an hour more a day with their children than parents did 25 years ago. d. Jane's job will have a negative effect on her children's well being, especially her daughter's.