Neddine Parker is up by 7 in the morning. After her morning exercises and some housework, she drives to the local hospital, where she volunteers once a week. What makes Parker's routine so extraordinary is that she is 104 years old. "I don't know why I'm still here," she said. Dr. Thomas Perls of the Boston University Medical Center is trying to figure that out. As the director of the New England Centenarian   Study, he studies there "super humans", those age 100 years and older. "It's like winning the lottery", he said. "You've got to choose the right numbers and the right combination." Researchers believe about 30 percent of aging is genetic. For those who get to extremely old ages, family history may play an even more important role. Reuben Landau's mother lived to 100, and three of his brothers and sisters into their 90s. Landau is nearly 102, and he still practices law a few hours every day. Both Landau and Parker are remarkably healthy. They take few medications and have no major illness. Perls has found that many centenarians lack a type of gene -- E4 -- that is associated with an increased risk of heart disease. One study found the gene is in 29 percent of young men, but only 15 percent of centenarians. Perls also believes they may have a "protective gene", one that helps them survive what might kill others. Parker, for example, smoked until she was 100 and had a stroke at 89. However, living into your 100s isn't just genetics. Aging successfully has much to do with environment and behavior. Landau watches what he eats and exercises his body and mind every day. He's convinced it's why he's still in good health. "People still have to do the right things to get to very old age," said Perls. So it's not just the cards you're dealt, but how you play the hand. By saying "It's like winning the lottery", Dr. Thomas Perls means   _  .
it is quite unusual to be a centenarian it is very difficult to find "super humans" it is a tough job investigating the aging process it takes a long time to win a lottery