单选题 Move over Methuselah. Future generations could be living well into their second century and still doing Sudoku, if life expectancy predictions are true. Increasing by two years every decade, they show no signs of flattening out. Average lifespan worldwide is already double what it was 200 years ago. Since the 19808, experts thought the increase in life expectancy would slow down and then stop, but forecasters have repeatedly been proved wrong.
The reason behind the steady rise in life expectancy is "the decline in the death rate of the elderly", says Professor Tom Kirkwood from Newcastle University. He maintains that our bodies are evolving to maintain and repair themselves better and our genes are investing in this process to put off the damage which will eventually lead to death. As a result, there is no ceiling imposed by the realities of the ageing process. "There is no use-by-date when we age. Ageing is not a fixed biological process," Tom says.
A large study of people aged 85 and over carried out by Professor Kirkwood discovered that there were a remarkable number of people enjoying good health and independence in their late 80s and beyond. With people reaching old age in better shape, it is safe to assume that this is all due to better eating habits, living conditions, education and medicine.
There are still many people who suffer from major health problems, but modern medicine means doctors are better at managing long-term health conditions like diabetes, high blood pressure and heart disease. "We are reaching old age with less accumulative damage than previous generations. We are less damaged," says Professor Kirkwood. Our softer lives and the improvements in nutrition and healthcare have had a direct impact on longevity.
Nearly one-in-five people currently in the UK will live to see their 100th birthday, the Office for National Statistics predicted last year. Life expectancy at birth has continued to increase in the UK—from 73.4 years for the period 1991 to 1993 to 77.85 years for 2007 to 2009. A report in Science from 2002 which looked at life expectancy patterns in different countries since 1840 concluded that there was no sign of a natural limit to life.
Researchers Jim Oeppen and Dr. James Vaupel found that people in the country with the highest life expectancy would live to an average age of 100 in about six decades. But they stopped short of predicting anything more.
"This is far from eternity: modest annual increments in life expectancy will never lead to immortality," the researchers said.
We do not seem to be approaching anything like the limits of life expectancy, says Professor David Leon from the London School of Hygiene and Tropical Medicine. "There has been no flattening out of the best of the best—the groups which everyone knows have good life expectancy and low mortality ," he says.
These groups, which tend to be in the higher social and economic groups in society, can live for several years longer than people in lower social groups, prompting calls for an end to inequalities within societies.
Within populations, genes also have an important role to play in determining how long we could survive for—but environment is still the most important factor.
It is no surprise that healthy-living societies like Japan have the highest life expectancies in the world. But it would still be incredible to think that life expectancy could go on rising forever. "I would bet there will be further increases in life expectancy and then it will probably begin to slow," says Tom, "but we just don"t know."

【正确答案】 D

【答案解析】[解析] 该题问的是文章一开始预言未来的一代在过百岁时仍然能够玩一种叫做数独的益智游戏，这种预言的目的是什么?A项说的是说明数独是一种健康生活方式，浏览本文可知本文重点不在于介绍数独游戏，而在于说明人类寿命的延长以及分析使寿命延长的一系列原因。因此A选项可以排除；B项说的是为了证明数独游戏能帮助人们回到玛土撒拉(传说中的吸血鬼长寿者)，这很明显脱离了文章大意要表达的意思。C项说的是未来的一代会喜欢数独游戏因为这个游戏现在很流行，本文围绕未来一代将会更加长寿论述，中心不在游戏；D项说的是暗示未来一代在过百岁时也会很聪明并且精力旺盛，与文章的中心最为接近，并且最靠近文章的主题思想。因此正确答案为D。