Assisters get up to speed on how best to explain the new health coverage choices during training on Sept. 25 at the Omni Shoreham Hotel in Washington, D.C. Morgan Walker/NPR hide caption

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A growing number of children are entering puberty at younger ages — sometimes as young as 6 or 7. But in many schools, sex education classes don't begin before the fifth grade. Cuneyt Hizal/iStockphoto.com hide caption

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Stressed out? Who isn't? Stress can cause physical changes in the brain that may be linked to Alzheimer's. iStockphoto.com hide caption

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Schoolgirls eat a free midday meal in Hyderabad, India, last month. India has offered such meals since the 1960s to persuade impoverished parents to send their children to school. A U.N. report released Tuesday finds modest progress in the worldwide fight against chronic hunger. Mahesh Kumar A./AP hide caption

itoggle caption Mahesh Kumar A./AP

Stephanie Groover of Independence Blue Cross provides information about coverage to commuters in Philadelphia on the opening day of the health insurance exchanges. Matt Rourke/AP hide caption

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A woman looks at the HealthCare.gov insurance exchange site on Tuesday in Washington, D.C. Karen Bleier/AFP/Getty Images hide caption

itoggle caption Karen Bleier/AFP/Getty Images

Then-Gov. Mitt Romney signs the Massachusetts health care bill in Boston on April 12, 2006. Brian Snyder/Reuters/Landov hide caption

itoggle caption Brian Snyder/Reuters/Landov

Health care delivery is expected to change, with more care provided by nurse practitioners and fewer people having a doctor for life. Images.com/Corbis hide caption

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