A healthy dose of sunshine may be the secret to staying young, British scientists have disclosed.

Vitamin D is produced naturally by the skin in response to sunlight and may help to slow the ageing process and protect against heart disease, according to the study.

Researchers from King's College London studied 2,160 women aged between 18 and 79, looking at their telomeres - a biological marker of ageing found in DNA.As people get older, their telomeres get shorter and they are easy to have illnesses.

But the study found women with high levels of vitamin D had comparatively longer telomeres - a sign of being biologically younger and healthier.

The study suggests vitamin D may help to slow down the ageing process of DNA, and therefore the ageing process as a whole.

Lead researcher Dr Brent Richards said: "These results are exciting because they prove for the first time that people who have higher levels of vitamin D may age more slowly than people with lower levels of vitamin D.

"This could help to explain how vitamin D has a protective effect on many ageing related diseases, such as heart disease and cancer."

He said further studies are required to confirm the findings.

Professor Tim Spector, head of KCL's twin research unit, and a co-author of the report, added: "Although it might sound absurd(荒谬的), it's possible that the same sunshine which may increase our risk of skin cancer may also have a healthy effect on the general ageing process."

Vitamin D made by the action of sunlight on the skin accounts for 90 per cent of the body's supply, but lower levels can also be obtained through food such as fish, eggs and breakfast cereals.

Other studies have suggested the vitamin plays a key role in protecting against cancer and heart disease.

58.What’s the best title of this passage?

  A.Sunshine helps to keep you young.

  B.Vitamin D has a protective effect on many diseases.

  C.Telomeres - a biological marker of ageing.

  D.People have found the secret to having a long life.

59.How can people get Vitamin D?

A.through water.       B. through sunshine.

C.through food.        D.both B and C.

60.Which of the following is not true according to the passage?

    A.women with high levels of vitamin D shows a sign of being biologically younger and healthier.

    B.vitamin D has a protective effect on many ageing related diseases.

    C.too much sunshine may increase our risk of skin cancer.

    D.It has been proved that sunshine helps to keep you young.

The world is not coming to an end on December 21, 2012, the US space agency insisted Monday in a rare campaign to dispel widespread rumors fueled by the Internet and a new Hollywood movie.

The latest big screen offering from Sony Picture, 2012, arrives in theaters on Friday, with a 200-million-dollar production about the end of the world supposedly based on myths backed by the Mayan calendar. It is claimed that the end of time will come as a Planet X---or Nibiru---heads toward or collides with the Earth.

Some websites accuse NASA of hiding the truth on the planet’s existence, but the US space agency condemned such stories as an “Internet hoax”. “There is no factual basis for these claims,” NASA said in a question-and-anwser posting on this website. “If such a cllision were real, astronomers would have been tracking it for at least the past decade, and it would be visible by now to the naked eye. Obviously, it does not exist. Credible scientists worldwide know of no threat associated with 2012,” it insisted. “After all, our planet has been getting along just well for more than four billion years,” added NASA.

There is another planet, Eris, floating in space. But the small planet similar to Pluto will remain safely fixed in the outer solar system and it can come no closer than four billion miles to the Earth, according to NASA.

Earlier theories set the disaster for May 2003, but when nothing happened the date was moved forward to the winter in 2012 to coincide with the end of a cycle of the ancient Mayan calendar.

NASA insisted the Mayan calendar in fact does not end on December 21, 2012, as another period begins immediately afterward.

And even if the planets were to line up as some have forecast, the effect on our planet would be “negligible(unimportant)”, NASA said.

“And while comets and asteroids (小行星) have always hit the Earth, big hits are very rare,” NASA noted. The last major impact was believed to be 65 million years ago, resulting in the end of dinosaurs.

“We have already determined that there are no threatening asteroids as large as the one that killed the dinosaurs,” the space agency said.

49. ______ played a key role in the spread of the rumors.

   A. A new book              B. The Internet and a new Hollywood movie

   C. NASA                   D. An Indian calendar

50. We can infer that ______.

   A. people didn’t take the rumor seriously

   B. Planet X --- or Nibiru does exist

   C. astronomers have been tracking Planet X for over ten years

   D. the rumor caused a panic among some people

51. NASA thinks that Eris ______.

   A. might have a threat to the Earth

   B. dosen’t have any threat to the Earth

   C. is too far away to be visible

   D. is similar to our planet, where life might exist

52. Which of the following is the best title?

   A. New Hollywood movie 2012

   B. December 21, 2012, Not the end of the world

   C. End of the ancient Mayan calendar

   D. How rumors came into being

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