A long-term American study shows the importance of early education for poor children. The study is known as the Abecedarian Project. It involved  more than one-hundred young children from poor families in North Carolina. Half of the children attended an all-day program at a high-quality childcare center. The center offered educational, health and social programs. Children took part in games and activities to increase their thinking and language skills and social and emotional development. The program also included health foods for the children The children attended the program from when they were a few weeks old until the age of five years. The other group of children did not attend the childcare center. After the age of five, both groups attended public school. Researchers compared the two groups of children. When they were babies, both groups had similar results in tests for mental and physical skills. However, from the age of eighteen months, the children in the educational child care program did much better in tests.  The researchers tested the children again when they were twelve and fifteen years old. The tests found that the children who had been in the childcare center continued to have higher average test results. These children did much better on tests of reading and mathematics.  A few years ago, organizers of the Abecedarian Project tested the students again. At the time, each student was twenty-one years old. They were tested for thinking and educational ability, employment, parenting and social skills. The researchers found that the young adults who had the early education still did better in reading and mathematics tests. They were more than two times as likely to be attending college or to have completed college. In addition, the children who received early education were older on average, when their first child was born.  The study offers more evidence that learning during the first months and years of life is important for all later development.  The researchers of the Abecedarian Project believe their study shows a need for lawmakers to spend money on public early education. They believe these kinds of programs could reduce the number of children who do not complete school and are unemployed. The Abecedarian Project has lasted  _  .
almost one year about five years no more than 15 years more than 20 years