before. Two months later, their brains are filled with protein “plaques” that also characterise the latter stage of the disease in humans.
Now researchers have managed to restore memories to mice with Alzheimer’s. This helps provide more evidence about how memories are lost during the early stages of the disease and may point to how, some time in the future, those memories might be brought back.
Susumu Tonegawa and his colleagues at the Massachusetts Institute of Technology used a technique known as optogenetics, which activates neurons (神经元) by shining light on them. As they report in Nature, the researchers prepared seven-month-old Alzheimer’s mice by injecting a harmless virus into the rodents’ dentate gyrus (齿状回区), a part of the hippocampus that helps to store fearful memories. The virus contains a gene for channelrhodopsin-2, a light-sensitive protein which forms pores (毛孔) in the cell membranes of neurons infected with the virus. These pores are closed in the dark, but open in response to blue light, flooding neurons with positively charged ions. The resulting pulse of current makes the neurons fire.
Using a standard lab test of memory, a mouse was placed in a box and given a small electrical shock to its feet. Normal mice remember this and freeze in fear if put back in the box the following day, but mice with Alzheimer’s jump about as usual. Yet when the researchers stimulated (刺激) the dentate gyrus of these mice with blue light, they also froze, suggesting that they were now able to recall the original shock.
Holding on to a fearful memory in the long term, however, requires the brain to strengthen the nerve connections that link memory of the box to experience of the shock. This long-term strengthening process goes away in the brains of Alzheimer’s patients. Consistent with this idea, the Alzheimer’s mice did not freeze when placed in the box but only when their neurons were illuminated (照射).
To help the Alzheimer’s mice keep their memory of the electric shock, the team flashed their dentate gyrus with blue light at 100 hertz, a frequency known to induce long-term strengthening. After this the Alzheimer’s mice froze in the box for at least six continuous days, suggesting they were able to remember the shock themselves.
Dr Tonegawa’s team found that stimulating neurons in the dentate gyrus other than those directly involved with holding the fear memory prevented Alzheimer’s mice from remembering their
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shocks in the long term. That suggests that unless the technique can be refined, deep-brain stimulation may not be effective.
62. Which of the following is the main finding of the research?
A. It provides more evidence and possible ways to recover lost memories. B. It tells us the influence of lost memories on mice. C. It proves that mice’s brains are full of protein “plaques”. D. It provides us with the way to do the experiment.
63. Which of the following statements about hippocampus is true? A. It is a light-sensitive protein.
B. It contains a gene for channelrhodopsin-2. C. It helps to memorize bad experience. D. It is a harmless virus injected into the mice.
64. _________ will NOT have the reaction of fear when placed in the box again? A. Mice given an electrical shock
B. Mice with Alzheimer’ disease D. The mice with neurons illuminated
C. The mice stimulated by blue light
65. Why is it hard for mice with Alzheimer to keep a fearful memory in the long run? A. Because their brain can’t strengthen certain nerve connections. B. Because the mice were given a small electrical shock to its feet. C. Because their dentate gyrus need flashing with blue light at 100 hertz. D. Because the nerve connections linking the memory disappear in the brain.
D
For the second time in two years, an American has won one of the most respected global awards in literature. At a ceremony in London on Tuesday night, George Saunders accepted the 2017 Man Booker Prize for Lincoln in the Bardo, his first novel.
The book is an impressive and experimental ghost story set in 1862. It explores the death of Willie Lincoln, President Abraham Lincoln’s 11-year-old son, who died of fever during the second year of the Civil War. Saunders, a Tibetan Buddhist, imagines Willie’s
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experiences in the “bardo,” a Buddhist state between the worlds of the living and the dead where Willie communicates with other dead souls, and where he watches his father visit his entombed body.
Writing in The Guardian earlier this year, Saunders described the process of creating the novel: “There is something wonderful in watching a figure appear from the stone, feeling the presence of something within you ... and also beyond you—something consistent, willful, kind and generous, that seems to have a plan, which seems to be: to lead you to your own higher ground.”
Saunders was the bookmakers’ favorite to win the award, but the victory by an American writer immediately after Paul Beatty claimed the prize for his novel The Sellout is controversial. Before 2014, the Man Booker was qualified only to writers from the Commonwealth and the Republic of Ireland. The decision to allow American writers to enter has disappointed authors including A.S. Byatt and Julian Barnes, who argue that the award’s main purpose was giving exposure to writers who were little-known in the broader American literary market. “The Americans have got enough prizes of their own,” Barnes told the Radio Times last year. Ron Charles, the book critic for The Washington Post, has also argued against the inclusion of Americans. “For any serious reader of fiction in this country,” Charles wrote in September, “the Americanization of the Booker Prize is a lost opportunity to learn about great books that haven’t already been publicly announced.”
Baroness Young, The Telegraph reported, stated that the judging panel was concerned only with the worth of the books on the shortlist(入围名单), which also included Mohsin Hamid’s refugee parable Exit West, Paul Auster’s complex epic 4321, Emily Fridlund’s coming-of-age tale The History of Wolves, and Fiona Mozley’s rural fable Elmet. “We’re only concerned with the book and what that book is telling us,” Young said. “Nationality is just not an issue.”
For Saunders, the prize is an extraordinary recognition of his first attempt into full-length novels. The 58-year-old writer was previously best-known for his short stories, which have won him four National Magazine Awards for fiction and a MacArthur Fellowship. He came to writing relatively late in life after studying geophysical engineering and working as a technical writer until 1996. The idea for Lincoln in the Bardo came to him, he wrote in The Guardian, during a visit to Washington, D.C., when his wife told him the story of a grief-stricken President Lincoln visiting Willie’s tomb to hold his son’s body. Saunders has often noted that the experience of writing for him feels like a way to transform pain and division into something positive. The author Zadie Smith,
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speaking with Saunders for Interview, noted that “what sets him apart is his willingness not only to go into the heart of darkness but to suggest possible routes out.” 66. Ron Charles’ words intended to tell us that ________. A. Saunders’ novel Lincoln in the Bardo was not serious B. the Man Booker shouldn’t include works written by American
C. the Man Booker lost the opportunity to learn about great works from America D. the judging panel was concerned only with the worth of books 67. Which of the following writers is probably from the UK?
A. Mohsin Hamid. B. Paul Beatty. C. Julian Barnes. D. Emily Fridlund. 68. Baroness Young gave some examples of the shortlist to illustrate _______. A. the prize was awarded based more on content than on nationality B. people should pay more attention to the nationality of the writers
C. the Telegraph supports Baroness Young’s opinion on the books on the shortlist D. 4321, The History of Wolves and Elmet were of the same significance as Exit West 69. What gave Saunders the inspiration to write the novel Lincoln in the Bardo? A. The experience of travelling in Washington D.C. B. To lead himself to his own higher ground.
C. To go into the hearts of darkness and to suggest possible routes out. D. His wife’s description of Lincoln holding his son’s body.
70. According to the last paragraph, which one of the following statements is true? A. Lincoln in the Bardo is Saunders’ first writing.
B. Saunders won four National Magazine Awards for novels. C. Zadie Smith thinks highly of Saunders. D. Saunders is only known for his short stories.
第Ⅱ卷 （两部分，共35分）
第四部分 任务型阅读（共10小题；每小题1分，满分10分）
请认真阅读下列短文，并根据所读内容在文章后表格中的空格里填入一个最恰当的单词。
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注意：每个空格只填1个单词。请将答案写在答题纸上相应题号的横线上。
Tourism broadens the thinking of the traveler and leads to culture contact between the hosts and guests from far-off places. This can benefit the locals, since tourists bring culture with them.
Tourism may help to preserve local customs, as when traditional shows, parades, celebration and festivals are put on for tourists. The musicals, plays and serious drama of London theatres and other kinds of nightlife are largely supported by tourists. Such events might disappear without the stimulus of tourism to maintain them.
On the other hand, tourism often contributes to the disappearance of local traditions and folk songs. Churches, temples and other similar places are treated as tourist attractions. This can be at the expense of their original function: how many tourists want to worship in the middle of a flow of atheist invaders (无神论侵犯者) ? Who would want to pray while curious onlookers walk back and forth with guide books, rather than prayer books in their hands?
Tourism may bring other indirect cultural consequences. Anxiety which already exists between ancient and more modern ways may be deepened by tourists' ignorance of local customs and beliefs. Tourists, if not actually richer, often seem more well-off than natives. The former may therefore feel superior, leaving the latter embarrassed about their lifestyles. The result may be an inferior feeling which hardly helps the sense of identity which is so important to regional culture. The poverty of locality can look even worse when contrasted with the comfortable hotel environment where the average life expectancy is 75 years, may well cause anger in Sierra Leone , where the local population can expect to live to no more than 41 years. The relative prosperity (繁荣) of tourism may encourage crime. In Gambia, unemployed young people offer to act as guides in return for money. When the tourism season is over they can no longer get wages that way so that they turn to stealing from the locals. All this affects the local social life and culture badly.
Culture erosion (侵蚀) can also take place at more unnoticeable levels. Greek villagers traditionally prided themselves on their hospitality (好客). They would put up travelers for free, feeding them and listening to their stories. To take money would have been a disgrace. That has changed now. Tourists exist to be exploited. Perhaps this is hardly surprising if the earnings from one room rented to a tourist can exceed a teacher's monthly salary.
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