Essentially, everyone has two ages: a chronological（按时间计算的）age, how old the calendar says you are, and a biological age, basically the age at which your body functions as it compares to average fitness or health levels.

“Chronological age isn’t how old we really are. It’s merely a number,” said Professor David Sinclair at Harvard University. “It is biological age that determines our health and ultimately our lifespan. We all age biologically at different rates according to our genes, what we eat, how much we exercise, and what environment we live in. Biological age is the number of candles we really should be blowing out. In the future, with advances in our ability to control biological age, we may have even fewer candles on our birthday cake than the previous one.

To calculate biological age, Professor Levine at Yale University identified nine biomarkers（生物标志）that seemed to be the most influential on lifespan by a simple blood test. The numbers of those markers, such as blood sugar and immune（免疫的）measures, can be put into the computer, and the algorithm（算式，算法）does the rest.

Perhaps what’s most important here is that these measures can be changed. Doctors can take this information and help patients make changes to lifestyle, and hopefully take steps to improve their biological conditions. “I think the most exciting thing about this research is that these things aren’t set in stone,” Levine said. “People can be given the information earlier and take steps to improve their health before it’s too late.”

Levine even entered her own numbers into the algorithm. She was surprised by the results. “I always considered myself a very healthy person. I’m physically active; I eat what I consider a fairly healthy diet. But I did not find my results to be as good as I had hoped they would be. It was a wake-up call,” she said.

Levine is working with a group to provide access to the algorithm online so that anyone can calculate their biological age, identify potential risks and take steps to improve their health in the long run. “No one wants to live an extremely long life with a lot of chronic（慢性的）diseases,” Levine said. “By delaying the development of mental and physical functioning problems, people can still be engaged in society in their senior years. That is the ideal we should be pursuing.”

46. Biological age depends on ______.

A. whether we can adapt ourselves to the environment

B. how well our body works compared with our peers’

C. when we start to take outdoor exercise

D. what the calendar says about our age

47. By saying “we may have even fewer candles on our birthday cake than the previous one” in Para. 2, the author means ______.

A. we don’t have to celebrate our birthday every year

B. we are chronologically older than last year

C. we might be less happy than the previous year

D. we may be biologically younger than the year before

48. According to Professor Levine, what is the most exciting thing about her research?

A. The measures are not fixed.

B. Health services can be set up.

C. The problems are not that serious.

D. The research results are written in stone.

49. What does the author want to tell us by Levine’s example in Para. 5?

A. It is necessary to change our diet regularly.

B. The test results may give us wrong information.

C. Waking up early in the morning is good for our fitness.

D. The algorithm can reveal our potential health problems.

50. The ultimate goal of Levine’s research is to ______.

A. free people from chronic diseases

B. work out a solution to genetic problems

C. keep people socially active even in old age

D. provide people with access to scientific theory

BDADC

46．B 细节理解题。根据第一自然段后半句对biological age 的定义确定。注意同义替代。

47．D 推理判断题。根据第二自然段综合判断。

48．A 细节理解题。根据第四自然段第一句和第三行后半句判断。

49．D 推理判断题。这种算法给出的信息能暴露我们潜在的健康问题，给人们敲响警钟。

50．C 细节理解题。根据最后一个自然段最后一句判断。注意主语代词that的指代。