BRIGHTON, N.Y. - Twins Rhea Spohner and Ruth Emblow celebrated their 100th birthday on Friday, a feat experts said happens in just one set of twins out of 100,000. The sisters live separately in apartments in the same senior citizens' complex, while their little sister, who is 94, lives nearby, they said. "We couldn't live together," Emblow told the Rochester Democrat and Chronicle newspaper. "We're exact opposites in everything." But they share a fondness for chocolate and enjoy watching figure skating on television, they told the newspaper. Looking many years younger than their age, they said they cook for themselves, with a little help from friends. Statistically, only one pair of twins out of 100,000 survives so long, James Vaupel, a demographer at Duke University in Durham, North Carolina, told the newspaper. Longevity runs in the family. The twins' mother died at age 101, their father lived to be 87 and all six of his sisters lived to be more than 90 years old, the twins said.