Read this excerpt from Leah Missbach Day’s foreword to Wheels of Change . Studies continue to prove that if a girl stays in school she will strengthen her family, community, and nation. A long list of benefits of educating a girl in a developing country compiled by the World Health Organization includes later marriages, smaller families, better hygiene, greatly increased likelihood that further children will receive education, and my favorite—greater confidence. What is the central idea of the excerpt?