New research has revived one of the longest standing,and biologically fundamental debates in the life sciences Is there a set limit to how long humans can live?The study 1 in the journal Science,suggests that maybe there isn't.It should be noted that this finding contradicts other 2 research by biologists and demographers,as Nature notes lateaus after a certain point for these"super-elderly"2 Researchers examined a population of nearly 4,000 Italians who were 105 years or older.That they found was that mortality risk The risk of death increases when someone 5 gets older,6 as they reach their 80s and 90s But,say Sapienza University's Elisabetta Barbi and University of Roma Tre's Francesco Lagona,after reaching the 7 old age of 105,the 8 of dying 9 the following year essentially drop down to 50%.The researchers 10 the quality of their dataset,asserting that their"estimates are 11 arti facts of aggregation that limited earlier studies and provide the best 12 to date for the existence of extreme-age mortality plateaus in humans.If a mortality plateau really does 13 at higher ages that theoretically means death doesn't have to be an inevitability Not all scientists have 14 that conclusion.For instance,a team from New York’s Albert Einstein College of Medicine analyzed the ages of the worlds oldest people and pegged the maximum length of human 15 at somewhere between 115 and 125 years.（For the curious:The oldest person ever in 16 history was a French lady named Jeanne Calment,who died at 122 years of age in 1997.By analyzing global demographic data,we show that improvements in 17 with age 18 decline after age 100,and that the age at death of the world s oldest person has not increased since th 1990s.Our results strongly suggest that the maximum 19 of humans is fixed and 20 natural constraints,wrote the Albert Einstein researchers in their 2016 report
16选？
A.recorded
B.documented
C.written
D.registered