Babies born in summer are more likely to become short-sighted in late life, a study has shown.
As many as a quarter of all cases of short-sightedness are caused by too great an exposure to sunlight in the first weeks of life, say eye experts.
They are advising all parents to put sunglasses on their babies during the first weeks.
Scientists had already established that over-exposure to sunlight caused short-sightedness in animals.
Researchers who compared the months in which babies were born with whether they needed glasses later on say the principle also applies to humans.
A study of almost 300,000 young adults─the largest of its kind─showed that those born in June and July had a 25 per cent greater chance of becoming severely short-sighted than those born in December or January. Research leader Professor Michael Belkin, of Tel Aviv University, said it was because prolonged illumination(光照) causes the eyeball to lengthen, causing short-sightedness.
Hence the more light a newborn is exposed to, the more the eyeball lengthens and the worse the short-sightedness will be.
The mechanism which lengthens the eyeball is associated with levels of melatonin(褪黑激素), a pigment (色素) which protects the skin against harmful rays of the sun.
In young babies not enough melatonin is released as protection, meaning they are more vulnerable to sunburn and changes to eyeball shape.
Sight expert Professor Daniel O’Leary, of Anglia Ruskin University in Cambridge, said “At the moment we don’t know the precise cause of why light exposure affects sight, but the evidence seems to prove that it is one of the reasons for people becoming short-sighted.”
1. Babies born in summer are more likely to be short-sighted ____________.
A. because the summer sun is too strong for babies
B. because babies born in summer have lengthened eyeballs
C. if they are exposed to much sunlight in the first weeks after they are born
D. if parents don’t know a proper way to protect their babies’ eyes
2. Melatonin is a kind of material to ___________.
A. prevent the eyes from becoming near-sighted
B. protect the skin from harmful sun rays
C. make our body strong
D. protect babies’ eyes from summer sun
3. From what Professor Daniel O’Leary says we can conclude that ___________.
A. there is no evidence that short-sightedness is related to exposure to sunlight
B. whether light exposure affects sight still needs to be further proved
C. he believes that light exposure can cause short-sightedness
D. he tries to give the cause of why light exposure affects sight
4. The underlined word “vulnerable” in the passage probably means __________.
A. easy to be harmed B. resistant
C. protective D. changeable
Researchers are placing robotic dogs (机器狗) in the homes of lonely old people to determine whether they can improve the quality of life for humans. Alan Beck, an expert in human-animal relationship, and Nancy Edwards, a professor of nursing, are leading the animal-assisted study concerning the influence of robotic dogs on old people’s depression, physical activity, and life satisfaction. “No one will argue that an older person is better off being more active, challenged, or stimulated (刺激) ,” Edwards points out. “The problem is how we promote(使……成为现实)that, especially for those without friends or help. A robotic dog could be a solution.”
In the study, the robot, called AIBO, is placed for six weeks in the houses of some old people who live alone. Before placing AIBO in the home, researchers will collect baseline data for six weeks. These old people will keep a diary to note their feelings and activity before and after AIBO. Then, the researchers will review the data to determine if it has inspired any changes in the life of its owner.
“I talk to him all the time, and he responds to my voice,” says a seventy-year-old lady.“When I’m watching TV, he’ll stay in my arms until he wants down. He has a mind of his own.”
The AIBOs respond to certain orders. The researchers say they have some advantages over live dogs, especially for old people. Often the elderly are disabled and cannot care for an animal by walking it or playing with it. A robotic dog removes exercise and feeding concerns.
“At the beginning, it was believed that no one would relate to the robotic dog, because it was metal and not furry,” Beck says. “But it’s amazing how quickly we have given up that belief.
“Hopefully, down the road, these robotic pets could become a more-valuable health helper. They will record their masters’ blood pressure, oxygen levels, or heart rhythms. AIBOs may even one day have games that can help stimulate older people’s minds.”
48. The purpose of Beck and Edwards’ study is to ______
A. understand human-animal relationship B. make lonely old people’s life better
C. find the causes of old people’s loneliness D. promote the animal-assisted research
49. In the research, the old people are asked to ______
A. note the activities of AIBOs B. keep AIBOs at home for 12 weeks
C. record their feelings and activity D. analyze the collected information
50. What is the advantage of AIBO over live dogs?
A. It is easier to keep at home. B. It can help the disabled people.
C. It responds to all the human orders. D. It can watch TV with its owner.
51. The author seems to suggest that the future robotic dogs may ______
A. cure certain diseases B. keep old people active
C. change people’s beliefs D. look more like real dogs
If you are lost in the mountains, stay calm in the face of darkness, loneliness, and the unknown. It will greatly increase your chances of survival (生存). Many people think that preparing necessary equipment and knowing how to use it are very important, but actually eighty percent of mountain survival is your reaction to fear.
Find a hiding place.
Unnecessary labor will make you sweat and make you cold. Find a hiding place around you before trying to start your own construction. If you are in a snow-covered area, you may be able to dig a cave in deep snow for protection from the wind. You should try to hide yourself in the middle of the mountain if possible. Stay out of the valleys — cold air falls, and the valley floor can be the coldest area on the mountain.
Signal rescuers for help.
The best time to signal rescuers is during the day. Signal for help from the highest point possible — it will be easier for rescuers to see you, and any sound you make will travel farther. If you take a box of matches and a space blanket (a special blanket for traveling), build three smoky fires and put your blanket — gold side facing out — on the ground.
Do not walk away.
It will make finding you more difficult, as search teams will be trying to follow your path and may miss you if you have gone off in a different direction. Searchers often end up finding a car with no one in it.
If you get frostbite (冻伤), do not rewarm the affected area until you’re out of danger.
You can walk on frostbitten feet, but once you warm the area and can feel the pain, you will not want to walk anywhere. Try to protect the frostbitten area and keep it dry until you are rescued.
36. When lost in the mountains, you can increase your chances of survival if you .
A. take a space blanket with you B. do more physical labor
C. try to find a car immediately D. walk as far as possible to find help
37. According to the passage, people most probably fail to survive if they .
A. do not take enough equipment B. stay in the middle of the mountain
C. do not keep themselves warm D. stay in a snow-covered area
38. What can we infer from the passage?
A. Don’t travel by yourself. B. Mountain traveling is dangerous.
C. Don’t get frightened in danger. D. Avoid going to unfamiliar places.
A study published in September suggests there is a surprising way to get people to avoid unhealthy foods: change their memories. Scientist Elizabeth Loftus of the University of California at Irvine asked volunteers to answer some questions on their personalities (个性) and food experiences. “One week later,” Loftus says, “we told those people we'd fed their answers into our smart computer and it came up with an account of their early childhood experiences.” Some accounts included one key additional detail (细节): “You got sick after eating strawberry ice-cream.” The researchers then changed this detail into a manufactured (人为促生的) memory through leading questions—Who were you with? How did you feel? By the end of the study, up to 41% of those given a false memory believed strawberry ice-cream once made them sick, and many said they'd avoid eating it.
When Loftus published her findings, she started getting calls from people begging her to make them remember hating chocolate or French fries. Unfortunately, it's not that easy. False memories appear to work only for foods you don't eat on a regular basis. But most important, it is likely that false memories can be implanted (灌输) only in people who are unaware of the mental control. And lying to a patient is immoral, even if a doctor believes it's for the patient's benefit.
Loftus says there's nothing to stop parents from trying it with their overweight children. “I say, wake up—parents have been lying about Father Christmas for years, and nobody seems to mind. If they can prevent diseases caused by fatness and all the other problems that come with that, you might think that's a more moral lie. Decide that for yourself.”
72. Why did Loftus ask the volunteers to answer some questions?
A. To improve her computer program. B. To find out their attitudes towards food.
C. To find out details she can make use of D. To predict what food they'll like in the future.
73. What did Loftus find out from her research?
A. People believe what the computer tells them.
B. People can be led to believe in something false.
C. People tend to forget their childhood experiences.
D. People are not always aware of their personalities.
74. According to the study, people may stop having a certain food if they ________.
A. learn it is harmful for health
B. lie to themselves that they don't want it
C. are willing to let doctors control their minds
D. think they once had a bad experience of eating it
75. What is the biggest concern with the method?
A. Whether it is moral. B. Who it is best for.
C. When it is effective. D. How it should be used.
While parents, particularly mothers, have always been attached to their infants (婴儿), societal conditions frequently made this attachment difficult to maintain (保持). First of all, the high infant death rate in the premodern times meant that such attachments often ended in hopelessness. Perhaps to prevent the sadness that infant death caused, a number of societal practices developed which worked against early attachment of mother and child.
One of these premodern attachment-discouraging practices was to leave infants unnamed until they had survived into the second year. Another practice that discouraged maternal (母亲的) attachment was tightly wrapping (包裹) infants. Wrapping effectively prevented the close physical interactions like stroking (抚摸) and kissing that are so much a part of modern mothers' and fathers' affection for their infants.
A third practice which had the same distancing effect was wet-nursing. Breast-feeding (母乳哺育) was not popular among the well-to-do in the early modern times; infants were often fed by wet nurses hired for the purpose. In some places, such as nineteenth-century France, city infants were sent to wet nurses in the country. Often a wet nurse would feed her own child first, leaving little milk for the city infant—who, in many cases, died. In Rouen, the death rate for children sent to a wet nurse was 35 percent.
68. Babies were unnamed until they were two so that _______.
A. an old social custom could be kept up B. maternal attachment could be maintained
C. they could have better chances to survive D. their parents would not be too sad if they died
69. Why were babies wrapped?
A. To protect them from the cold. B. To distance their mothers from them.
C. To make them feel more comfortable. D. To make it easy for their mothers to hold them.
70. Wet nurses were women who________.
A. babysat city infants B. fed babies of other families
C. sent their babies to the country D. failed to look after their babies
71. Which is the best title for the passage?
A. Societal Conditions in Premodern Times
B. Practices of Reducing Maternal Attachment
C. Poor Health Service and High Infant Death Rate
D. Differences between Modem and Premodern Parents
Millions of people visit Yosemite National Park every year to see the tall waterfalls and mountains. These mountains are a splendid sight when viewed form the valley floor. Lots of stores, hotels, and restaurants are needed to handle the crowds. Also, water, roads, and other service systems are part of the infrastructure (基础设施) that must be maintained.
Unfortunately, these systems are starting to break down. It’s not just in Yosemite but in national parks around the nation.
Yosemite is thirty years old according to Dennis Galvin, a National Park Service worker. The Park is not only old but worn out. Two or three times as many visitors come every year. That is too many visitors for the park to deal with.
Four years ago a storm washed out a water pipeline in the Grand Canyon. The National Park Service had to send water trucks to provide water for the visitors. Last month pipes almost broke again and roads had to be closed for a while.
Why hasn’t the National Park Service kept up the park repairs? There is a lack of money. The United States has 378 monuments, parks, and wilderness areas. Between three and four billion dollars are needed for repairs.
Yosemite is one national park that does have money for repairs. It has two hundred million dollars but cannot spend it any way it chooses. When the park workers started widening the road, they were forced to stop by the Sierra Club. The club claimed that the road work was damaging the Merced River that runs through the park.
A sierra Club lawyer, Julia Olson, feels that the infrastructure needs to be moved out of Yosemite. That way less pressure will be put on the already crowded park.
65.According to the text, the mountains in Yosemite look most splendid when they are appreciated from ______.
A. the bottom of the valleys B. the top of the mountains
C. the side of the mountains D. the edge of the valleys
66.National parks like Yosemite in the U.S. find it increasingly difficult to meet the need of
visitors because ______.
A. their transport management needs improving
B. they spend too much on their service systems
C. their service systems frequently go out of order
D. they need help from environmental organizations
67.The main problem of Yosemite National Park is its ______.
A. rundown water pipes B. overcrowdedness
C. lack of money D. narrow roads
68. According to the text, the Sierra Club is most likely to be ______.
A. an environmental groupB. an information center
C. a travel serviceD. a law firm