第二部分 阅读理解（共25小题；每小题2分，满分50分）
阅读下面短文，掌握其大意，然后从21~45各题所给的四个选项（A、B、C、D）中，选出最佳选项，并在答题卡上将该项涂黑。
Passage A
Visitors from space may have landed on our planet dozens, even hundreds of times during the long, empty ages while Man was still a dream of the distant future. Indeed, they could have landed on 90% of the earth as recently as two or three hundred years ago, and we could never have heard of it. If one searches through old newspapers and local records, one can find many reports of strange incidents that could be interpreted(解释) as visits from outer space. A winter, Charles Fort, had made a collection of UFO sightings in his book. One is tempted(引诱) to believe them more than any modern reports, for the simple reason that they happened long before anyone had ever thought of space travel. Yet at the same time, one can’t take them too seriously, for before scientific education was widespread, even sightings of meteors(流星) and comets(彗星) gave rise to the most unbelievable stories, as they still do today.
1. According to the passage visitors from space may have landed on the earth _____.
A. long before man had dreamed of it
B. long before there were human beings
C. in the last few hundred years
D. after the space age began
2. According to the passage, which of the following statements is true?
A. All observations of UFO’s are believable
B. Charles Fort sighted a lot of UFO’s himself
C. Older civilization (文明) may exist on other planets
D. People have seen visitors from other planets everywhere
3. If visitors from other planets have actually landed on the earth, one can suppose that they came to __________________.
A. make war B. communicate C. settle down D. explore
4 The passage implies that the space age has __________________.
A. made the reported sightings unbelievable
B. increased the number of UFO sightings
C. allowed more scientific study of UFO’s
D. given clearer pictures of UFO’s
5. According to the passage, __________________.
A. UFO’s are only recent observations B. UFO sightings are not new
C. UFO’s are just meteors and comets D. UFO’s are invented by people
Scientists have long puzzled over how iguanas, a group of lizards(蜥蜴) mostly found in the Americas, came to live in the isolated Pacific islands of Fiji and Tonga. Some scientists used to suppose that they must have traveled there on a raft, a journey of around 5,000 miles from South America to the islands. There are documented cases of iguanas reaching remote Caribbean islands and the Galapagos Islands on floating logs. But new research in January by Brice Noonan and Jack Sites suggested that iguanas may have simply walked to Fiji and Tonga when the islands were still a part of an ancient southern supercontinent.
The ancient supercontinent was made up of present-day Africa, Australia, Antarctica and parts of Asia. If that’s the case, the island species would need to be very old. Using “molecular (分子) clock” analysis of living iguanas’ DNA, Noonan and Sites found that, sure enough, the lineage of iguanas has been around for more than 60 million years—easily old enough to have been in the area when the islands were still connected by land bridges to Asia or Australia.
Fossils (化石) uncovered in Mongolia suggest that iguanid ancestors did once live in Asia. Though there’s currently no fossil evidence of iguanas in Australia, that doesn’t necessarily mean they were never there. “The fossil record of this continent is surprisingly poor and cannot be taken as evidence of true absence,” the authors write.
So if the iguanas simply walked to Fiji and Tonga from Asia or possibly Australia, why are they not also found on the rest of the Pacific islands? Noonan and Sites say fossil evidence suggests that iguana species did once inhabit other islands, but went extinct right around the time when humans settled in those islands. But Fiji and Tonga have a much shorter history of human presence, which may have helped the iguanas living there to escape extinction.
The researchers say that their study can’t completely rule out the rafting theory, but it does make the land bridge theory “far more reasonable than previously thought.” What did some scientists previously believe about the iguanas?
| A．They were once discovered in America. |
| B．They traveled by raft to Fiji and Tonga. |
| C．They could survive in poor living conditions. |
| D．They moved to Fiji and Tonga from Australia. |
According to Noonan and Sites, 60 million years ago ____.
| A．the land of the world was a supercontinent |
| B．Fiji and Tonga were connected to Asia or Australia |
| C．Africa, Australia and America were a continent |
| D．iguanas walked to Fiji and Tonga from Africa |
The underline word “lineage” in Paragraph 2 probably refers to ____.
| A．conditions in which creatures can survive |
| B．the change in ancient plants and animals. |
| C．the line of generations of an ancestor |
| D．the habitat of a type of an ancient animal |
What is the main topic of this passage?
| A．The life span of animals living on the ancient supercontinent. |
| B．The two islands being home to several iguana species in the Pacific region. |
| C．The fossil evidence suggesting iguanas’ ancestors’ swimming to Fiji and Tonga |
| D．By raft or by land — how did iguanas reach the tiny Pacific islands? |
Sometime in the next century, the familiar early-newspaper on the front porch (门廊) will disappear. And instead of reading your newspaper, it will read to you. You'll get up and turn on the computer newspaper just like switching on the TV An electronic voice will distribute stories about the latest events, guided by a program that selects the type of news you want. You'll even get to choose the kind of voice you want to hear. Want more information on this brief story? A simple touch makes the entire text appear. Save it in your own personal computer if you like. These are among the predictions from communication experts working on the newspapers of the future. Pictured as part of broader home-based media and entertainment systems, computer newspapers will unite print and broadcast reporting, and offer news and analysis with video images of news events.
Most of the technology is available now, but convincing more people that they don't need to read a newspaper is the next step. But resistance to computer newspapers may be stronger from within journalism. Since it is such a cultural change, it may be that the present generation of journalists and publishers will have to die off before the next generation realizes that the newspaper industry is no longer a newspaper industry. Technology is making the end of ' traditional newspapers unavoidable.
Despite technological advances, it could take decades to replace newsprint with computer screens. It might take 30 t0 40 years to complete the changeover because people need to buy computers and because newspapers have established financial interests in the paper industry. Which of the following is NOT an advantage of computer newspapers?
| A．They are cheaper than traditional newspapers. |
| B．They are more convenient to read. |
| C．You can choose the kind of voice you want to hear. |
| D．You can easily save information for future use. |
Which of the following is a reason why it will take a long time to complete the changeover?
| A．The technology is impossible now. |
| B． Computer newspaper s are too expensive. |
| C．The popularization of computers needs a long time. |
| D．Traditional newspapers are easier to read. |
It can be inferred that journalists are against computer newspapers because _______ .
| A．they don't know how to use computers |
| B．they think computer newspapers take too much time to read |
| C．they think the new technology is bad |
| D．they have been trained to write For traditional newspapers |
We can infer from the passage that
| A．all technological changes are good |
| B．new technologies don't always replace old ones |
| C．new technologies will eventually replace old ones |
| D．traditional newspapers are here to stay for another century |
What is the best title of the passage?
| A．Computer newspapers are well liked. |
| B．Newspapers of the future will be on the computer. |
| C．Newspapers are out of fashion. |
| D．New communications technology. |
Losing weight comes with a lot of health benefits—including making your brain sharper.
Yes, it turns out that overweight may damage cognitive functions (认知功能) such as memory and attention. There have been few studies of overweight and cognitive functioning, possibly because it is generally believed that it is not a primary risk cause for poor cognitive performance. Losing weight, therefore, may help improve these mental functions, according to a new research led by John Gunstad, assistant professor of psychology at Kent State University.
Growing evidence suggests that being fat is linked to cognitive deficits (缺陷). So Gunstad and his team guessed that losing weight might improve mental function. For their study, they measured memory and attention in a group of 150 overweight participants, some of whom had some kind of operation for weight loss and some did not. All of the volunteers completed mental skills tests to assess their abilities of memory and attention at the beginning of the study, and again 12 weeks later. To begin with, about 24% of the patients showed damaged learning and 23% showed signs of poor memory when tested. At the end of the study, those who had lost weight after operation improved their scores into the average or above average range for cognitive functions. Scores for the volunteers who didn’t lose weight dropped even further.
The study helped Gunstad to find out whether losing weight had any effect on mental function. Now that he’s seen the positive effect that weight loss can have on memory and attention, he says he will next study those who choose to lose weight by the traditional way—eating healthier and getting more active. He expects that losing weight in this way will have a similarly positive effect on the brain. “If we can improve the condition with operations, then we can probably produce the same change with behavioral weight loss as well,” he says. There is less research on overweight and cognitive functions because researchers _____.
| A. believe overweight only affects our body |
| B. have focused on ways to sharpen people’s mind |
| C. do not consider overweight a main cause for low cognitive ability |
| D. are clear about the relation between weight and mental functions |
The result of Gunstad’s study shows that ______.
| A. losing weight has little effect on people’s memory |
| B. losing weight can improve people’s mental functions |
| C. overweight people are likely to have psychology problems |
| D. overweight people’s abilities of concentration differ greatly |
What is Gunstad planning to prove next in his research?
| A. Slim people are smarter than overweight people. |
| B. Healthy diet is better than exercise in losing weight. |
| C. Traditional ways of losing weight are better than operation. |
| D. Overweight people will get smarter by taking more exercise. |
Which of the following is the best title for the text?
| A. Body Weight and Health |
| B. Losing Weight by Operation |
| C. Ways to Improve Mental Functions |
| D. Losing Weight to Sharpen Your Mind |
Caffeine not only gives us a daily jump start, but new research suggests it also can strengthen long-term memory.
According to the US Food and Drug Administration, nearly 90 percent of people worldwide consume about 200 milligrams of caffeine each day. That' s equivalent to about one strong cup of coffee a day. Writing in " Nature Neuroscience" , Johns Hopkins University researchers say their findings show that caffeine strengthens certain memories for up t0 24 hours after being taken in.
" We've always known that caffeine has cognitive-enhancing effects (促智效果) , but its ,particular effects on strengthening memories and making them resistant to forgetting has never been examined in detail in humans, " said senior author of the paper Michael Yassa. " We re- port for the first time a specific effect of caffeine on reducing forgetting over 24 hours. " Conducting a double-blind trial, the researchers worked with a test group of people who didn't regularly consume caffeinated products. Five minutes after studying a series of images, the test subjects were given either a placebo(无效对照剂) or a 200-milligram caffeine tablet.
To check the caffeine levels of their test subjects, the research team took saliva samples (唾液样品) from them before they took their tablets and again one, three and 24 hours after- wards.
Both groups of test participants ( those who took the placebo and those who took the caffeine tablet) were tested the following day to see if they could recognize the images they' d seen the previous day.
The test included showing the test subjects another series of images that included some new images , those that were shown the previous day, as well as other images that were similar, but not the same as those they had viewed earlier.
The researchers found that more members of the group who were given the caffeine tablets were able to correctly identify some of the new images as " similar" to previously viewed images rather than incorrectly identifying them as the same.
"We also know that caffeine is associated with health and longevity(长寿) and may havesome protective effects from cognitive decline like Alzheimer' s disease (阿尔茨海默症). " said Yassa.The purpose of the new research is
| A．to survey how much caffeine people consume a day |
| B．to write the paper " Nature Neuroscience" |
| C．to prove caffeine has cognitive-enhancing effects |
| D．to examine caffeine ' s memory-strengthening effects in detail |
During the research ,the researchers did the following things EXCEPT
| A．giving the test subjects placebos or caffeine tablets |
| B．checking the caffeine levels of the test subjects |
| C．encouraging the test subjects to drink more coffee |
| D．showing the test subjects series of images |
How did the test subjects show the caffeine ' s memory-strengthening effects?
| A．By recognizing images they ' d seen the previous day. |
| B．By taking the caffeine tablets instead of placebos. |
| C．By identifying the new images as the same. |
| D．By telling the differences between new images. |
What will the next part of the text possibly talk about?
| A．Ways to achieve health and longevity. |
| B．The effects caffeine has on health. |
| C．The treatment for Alzheimer' s disease. |
| D．The harmful effects of cognitive decline. |
The preventive measures for forest fires include some preemptive(抢先)methods that can help reduce the risks of fires and control their severity and spread，and thus, maintain ecological balance and protect resources．Close monitoring of forest fires caused by natural factors can help prevent their spread to a large extent．To contain forest fires，fire departments usually use water and chemical fire retardants(抑制剂)that can be dropped from planes and helicopters．To control the spread of a wildfire．firefighters usually create a control line by removing all fuel from an area so that the fire cannot travel across it．
Controlled burns are often employed by government authorities to reduce fuel buildup，and clean up the fallen leaves，and thus，prevent the spread of forest fires to a vast area．Regular controlled burns can also help maintain biodiversity(生物多样性)，as the smoke and heat produced in the process can facilitate(促进)the growth of seeds of certain plant species．Apart from these，responsible human behavior can help reduce the number of forest fires to a great extent．In fact，we can reduce the number of wildfires dramatically by not leaving behind any source of fire in the forest.
Forest fires can affect climate and weather to a great extent，besides causing severe damage to valuable trees．Wildfires can increase the level of greenhouse gases(water vapor, carbon dioxide，etc)，and therefore increase pollution and global warming．However, they are also an important part of the ecosystem，and many plants depend on the heat and smoke generated by wildfires for their growth and reproduction．But large wildfires can cause extensive damage to the ecosystem，which again highlights the importance of effective control and prevention of forest fires·What may be the best title for this passage?
| A．Control and Prevention of Forest Fires |
| B．How to Keep Ecological Balance |
| C．Effects of Forest Fires |
| D．Methods of Fire Spread Control |
Firefighters get rid of all fuel in all area in order to ____________．
| A．keep close monitoring of forest fires |
| B．prevent the forest fire from occurring |
| C．protect the animals there |
| D．stop the wildfire from spreading |
The government arranges some controlled burns to_______________．
| A．burn the rubbish and keep the forest clean |
| B．help keep ecological balance of nature |
| C．reduce fuel buildup and limit forest fires spread |
| D．provide reasonable conditions for some plants’growth |
A controlled forest fire may play a positive role because ________________.
| A．a new forest will appear soon |
| B．it promotes the development of some seeds |
| C．nature keeps its balance only by wildfires |
| D．it makes the trees grow faster than before |
The last paragraph tells us that _______________．
| A．the greenhouse gases are caused mainly by wildfires |
| B．wildfires have both positive and negative effects |
| C．people should be aware of the necessity of wildfires |
| D．all the valuable trees disappear owing to wildfires |