to sunlight for too much time will do harm to one’s skin. A．Being exposed B．Exposed C．Having exposed D．After being exposed 题目和参考答案——青夏教育精英家教网—

题目内容

to sunlight for too much time will do harm to one’s skin.

A．Being exposed B．Exposed

C．Having exposed D．After being exposed

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Passage Eleven (Superconducting Materials)

The stone age, The Iron Age. Entire epochs have been named for materials. So what to call the decades ahead? The choice will be tough. Welcome to the age of superstuff. Material science -- once the least sexy technology – is bursting with new, practical discoveries led by superconducting ceramics that may revolutionize electronics. But superconductors are just part of the picture: from house and cars to cook pots and artificial teeth, the world will someday be made of different stuff. Exotic plastics, glass and ceramics will shape the future just as surely as have genetic engineering and computer science.

The key to the new materials is researchers’ increasing ability to manipulate substances at the molecular level. Ceramics, for example, have long been limited by their brittleness. But by minimizing the microscopic imperfections that cause it, scientists are making far stronger ceramics that still retain such qualities as hardness and heat resistance. Ford Motor Co. now uses ceramic tools to cut steel. A firm called Kyocera has created a line of ceramic scissors and knives that stay sharp for years and never rust or corrode.

A similar transformation has overtaken plastics. High-strength polymers now form bridges, ice-skating rinks and helicopter rotors. And one new plastic that generates electricity when vibrated or pushed is used in electric guitars, touch sensors for robot hands and karate jackets that automatically record each punch and chop. Even plastic litter, which once threatened to permanently blot the landscape, has proved amenable to molecular tinkering. Several manufacturers now make biodegradable forms; some plastic six-pack rings for example, gradually decompose when exposed to sunlight. Researchers are developing ways to make plastics as recyclable as metal or glass. Besides, composites – plastic reinforced with fibers of graphite or other compounds – made the round-the-world flight of the voyager possible and have even been proved in combat: a helmet saved an infantryman’s life by deflecting two bullets in the Grenada invasion.

Some advanced materials are old standard with a new twist. The newest fiberoptic cable that carry telephone calls cross-country are made of glass so transparent that a piece of 100 miles thick is clearer than a standard window pane.

But new materials have no impact until they are made into products. And that transition could prove difficult, for switching requires lengthy research and investment. It can be said a firmer handle on how to move to commercialization will determine the success or failure of a country in the near future.

1.How many new materials are mentioned in this passage?

A.Two B.Three C.Four D.Five

2.Why does the author mention genetic engineering and computer science?

A.To compare them with the new materials.

B.To show the significance of the new materials on the future world.

C.To compare the new materials to them.

D.To explain his view point.

3.Why is transition difficult?

A.Because transition requires money and time.

B.Because many manufacturers are unwilling to change their equipment.

C.Because research on new materials is very difficult.

[D]Because it takes 10 years.

4.Where lies success of a country in the New Age of superstuff?

A.It lies in research.

B.It lies in investment.

C.It lies in innovation.

D.It lies in application.

_____ to sunlight for too much time will do harm to one's skin.

A. Exposed B. Having exposed C. Being exposed D. After being exposed

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.

64．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

65．How can people get vitamin D?

A．through water B．through sunshine

C．through food D．both B and C

66．What does the underlined word in paragraph three refer to?

A．It refers to a kind of vitamin that can keep you young.

B．It refers to a biological marker of ageing found in DNA.

C．It refers to a kind of element that can be obtained from sunshine.

D．It refers to a part of the body.

67．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'.

CHICAGO （Reuters） - Smoking not only can wrinkle （起皱纹） the face and tarn it yellow—it can do the same to the whole body, researchers reported on Monday．
The study, published in the Archives of Dermatology, shows that smoking affects the skin all over the body—even skin protected from the sun．
"We examined non - facial skin that was protected from the sun, and found that the total number of packs of cigarettes smoked per day and the total years a person has smoked were linked with the amount of skin damage a person experienced," Dr．Yolanda Helfrich of the University of Michigan, who led the study, said in a statement．
"In participants older than 65 years, smokers had significantly more fine wrinkling than nonsmokers．Similar findings were seen in participants aged 45 to 65 years," Helfrich "s team added in their report．
The researchers tested 82 people, smokers and nonsmokers, taking pictures of the inner right arms． They ranged, in age from 22 to 91 and half were smokers．Independent judges decided how wrinkled each person' s skin was．
When skin is exposed to sunlight, notably the face, it becomes coarse, wrinkled and discolored with a pale yellow tint, Helfrich ' s team wrote．
Several previous studies have found that cigarette smoking contributes to premature（过早的）skin aging as measured by facial wrinkles, the study said, but little has been done to measure the aging of skin not exposed to light．
The report did not discuss die mechanism involved but previous research has found that cigarette smoke, among other things, causes blood vessels （血管） beneath the skin to constrict （紧缩）, reducing blood supply to the skin．
Smoking can also damage the connective tissue that supports both die skin and the internal organs,．
【小题1】When your skin is exposed to sunlight long, it-becomes all of the following but _____．