John R. Wilmoth, a demographer (人口统计学家) at the University of California, Berkeley, has (11) a wealth of (12) on humankind’s increasing longevity (寿命) over the past two centuries. And this week in Science(美国《科学》杂志), he has some good news: The maximum (13) age we can reach too is on the rise. This finding contradicts the common scientific belief that life span has a biological upper (14) of 120 years or so. "Whether 115 or 120 years, it is a legend created by (15) who are quoting each other," Wilmoth says.