Primary colors are not a fundamental property of light but are related to the color vision system in animals. The human eye normally contains only three types of color photoreceptors (L, M and S) that are associated with specialized cone cells.
No. 15; Updated October 2015. Approximately 120,000 children are adopted each year in the United States. Children with physical, developmental, or emotional handicaps who were once considered difficult to place with a new family are now being adopted (special needs adoptions). Adoption helps many of these children to grow up in permanent families rather than in foster homes or institutions.
In the 1990s, there are approximately 120,000 adoptions of children each year. 104,000 children were adopted in 1986, 53,000 of whom were related adoptions and 51,000 of whom were unrelated. In addition, approximately 10,000 children were adopted from abroad, bringing the total number of unrelated adoptions to 61,000. (Bachrach, London, Maza, 1991) The estimated total number of adoptions has ranged from a low of 50,000 in 1944 to a high of 175,000 in 1970.