1 . On March 7, 1907, the English statistician Francis Galton published a paper which illustrated what has come to be known as the “wisdom of crowds” effect. The experiment of estimation he conducted showed that in some cases, the average of a large number of independent estimates could be quite accurate.
This effect capitalizes on the fact that when people make errors, those errors aren’t always the same. Some people will tend to overestimate, and some to underestimate. When enough of these errors are averaged together, they cancel each other out, resulting in a more accurate estimate. If people are similar and tend to make the same errors, then their errors won’t cancel each other out. In more technical terms, the wisdom of crowds requires that people’s estimates be independent. If for whatever reasons, people’s errors become correlated or dependent, the accuracy of the estimate will go down.
But a new study led by Joaquin Navajas offered an interesting twist (转折) on this classic phenomenon. The key finding of the study was that when crowds were further divided into smaller groups that were allowed to have a discussion, the averages from these groups were more accurate than those from an equal number of independent individuals. For instance, the average obtained from the estimates of four discussion groups of five was significantly more accurate than the average obtained from 20 independent individuals.
In a follow-up study with 100 university students, the researchers tried to get a better sense of what the group members actually did in their discussion. Did they tend to go with those most confident about their estimates? Did they follow those least willing to change their minds? This happened some of the time, but it wasn’t the dominant response. Most frequently, the groups reported that they “shared arguments and reasoned together”. Somehow, these arguments and reasoning resulted in a global reduction in error. Although the studies led by Navajas have limitations and many questions remain, the potential implications for group discussion and decision-making are enormous.
1. What is paragraph 2 of the text mainly about?| A．The methods of estimation. | B．The underlying logic of the effect. |
| C．The causes of people’s errors. | D．The design of Galton’s experiment. |
| A．the crowds were relatively small | B．there were occasional underestimates |
| C．individuals did not communicate | D．estimates were not fully independent |
| A．The size of the groups. | B．The dominant members. |
| C．The discussion process. | D．The individual estimates. |
| A．Unclear. | B．Dismissive. | C．Doubtful. | D．Approving. |
2 . It’s late in the evening, time to close the book and turn off the computer. You’re done for the day. What you may not realize, however, is that the learning process actually continues in your dreams.
It might sound like science fiction, but researchers are increasingly focusing on the relationship between the knowledge and skills our brains absorb during the day and the often strange imaginings they generate at night. Scientists have found that dreaming about a task we’ve learned improves performance in that activity (suggesting that there’s some truth to the popular idea that we’re “getting” a foreign language once we begin dreaming in it). What’s more, dreaming may be an essential part of understanding, organizing and retaining what we learn.
While we sleep, research indicates, the brain replays the patterns of activity it experienced during waking hours, allowing us to enter what one psychologist calls a neural (神经的) virtual reality. A vivid example of such replay can be seen in a video researchers made recently about sleep disorders. They taught a series of dance moves to patients suffering from sleepwalking and related conditions. They then videotaped the subjects as they slept. Lying in bed, eyes closed, one female patient on the tape performs the dance moves she learned earlier.
This shows that while our bodies are at rest, our brains are drawing what’s important from the information and events we’ve recently encountered, then integrating that material into the vast store of what we already know. In a 2010 study, researchers reported that college students who dreamed about a computer maze (迷宫) task they had learned showed a 10-fold improvement in their ability to find their way through the maze compared with participants who did not dream about the task.
That study’s chief researcher Herbert Smith suggested that studying right before bedtime or taking a nap following a study session in the afternoon might increase the probability of dreaming about the material. Think about that as you go to sleep tonight.
1. What happens when one enters a dream state?| A．The body continues to act as if the sleeper were awake. |
| B．The neural activity of the brain will become intensified. |
| C．The brain once again experiences the learning activities of the day. |
| D．The brain behaves as if it were playing a virtual reality video game. |
| A．It replaces old information with new material. |
| B．It processes and absorbs newly acquired information. |
| C．It regroups information and places it in different files. |
| D．It systematizes all the information collected during the day. |
| A．Staying up late before finally going to bed. |
| B．Having a period of sleep right after studying. |
| C．Having a dream about anything you are interested in. |
| D．Thinking about the chances of dreaming about the material. |
| A．How study affects people’s dreams. |
| B．Why people learn more after sleeping. |
| C．What time students should study and sleep. |
| D．How dreaming may lead to improved learning outcomes. |
3 . A block chain is a data structure that stores time-ordered data in an ever-growing list, like an accounting ledger (分类账簿). The block chain data structure is maintained using a distributed, peer-to-peer network of computers with no central “master”. As with many new concepts, block chain technology generates much optimism and also a huge amount of interest and excitement. Just what is it good for?
In short, block chains may improve any process where people need to access, confirm, send or store information securely. This information could be a person’s identity, a product’s shipment history or digital property like money.
Typical databases, spreadsheets (电子数据表), and ledgers store information about objects, people, and the interactions between them. Much of the world’s information, from credit card transactions to medical and financial records, is stored in these types of systems.
These types of systems have considerable, well-documented weaknesses that arise from their being centralized. A centralized record is hard to understand and is exposed to unauthorized access or distribution. It is also, because it is a ‘master’ copy, exposed to permanent changing or deletion.
Block chains are also used to store information. Crucially, however, they differ in two ways.
First, information is parceled up into blocks and sealed. Bitcoin, for example, which is the most famous practical example of a production block chain, stores all transactions across the network every ten minutes or so in a single, newly formed block. Each block is then added to the previous one to form a chain.
Second, this “chain of blocks” is not stored centrally. Instead, each block is copied and distributed around an entire network of peers - be they individuals, public institutions, or businesses - using distributed ledger technology. (The terms “block chain” and “distributed ledger” are often used interchangeably; for the sake of clarity, block chain technologies tend to employ distributed ledger technology.)
Each time someone adds a new block to the chain, meanwhile it is added to everyone’s copy.
1. What is the biggest strength of a block chain?| A．It promotes people’s enthusiasm about new technology. |
| B．It strengthens the security of processing information. |
| C．It enables people to store more data in time order. |
| D．It stores a large part of world’s information. |
| A．they are difficult to operate | B．they can be accessed easily |
| C．they have a central “master” | D．they store considerable documents |
| A．making comparisons | B．giving examples |
| C．making a list | D．showing the effect and causes |
| A．To analyze the weaknesses of typical systems. |
| B．To encourage the popularity of the block chain. |
| C．To introduce the new concept of the block chain. |
| D．To compare the two different data structures. |
4 . Antarctica(南极洲)’s melting ice, which has caused global sea levels to rise by at least 13.8 millimeters over the past 40 years, was thought to primarily come from the unstable West Antarctic Ice Sheet(WAIS). Now, scientists have found that the East Antarctic Ice Sheet (EAIS)—considered largely unaffected by climate change—may also be melting at an unexpectedly rapid speed.
The WAIS, whose base is below sea level, has long been considered the most likely to break down. Besides gravity, a deep current of warm water slips beneath the sheet, melting it from below until it becomes a floating shelf at risk of breaking away. In contrast, extreme cold and a base mostly above sea level are thought to keep the EAIS relatively safe from warm waters.
But as greenhouse gases warm much of the planet, driving stronger polar winds, some scientists think warm water carried by a circular current will start to invade East Antarctica’s once unassailable ice. A cooperation of more than 60 scientists last year, published in Nature, estimated that the EAIS actually added about 5 billion tons of ice each year from 1992 to 2017.
Eric Rignot of the University of California, Irvine, and colleagues combined 40 years of satellite imagery and climate modeling and found that overall Antarctica now sends six times more ice into the sea each year than it did in 1979, with the majority coming from West Antarctica. But East Antarctica was responsible for more than 30% of Antarctica’s contribution to the 13.8-millimeter sea level rise over the past 40 years. “The more we look at this system the more we realize this is fragile,” Rignot says. “Once these glaciers become unstable there is no red button to press to stop it.”
Rignot hopes the study brings greater attention to a part of Antarctica that has traditionally been understudied. Helen Fricker, a glaciologist (冰川学家) in California, agrees. “We need to monitor the entire Antarctica and we just can’t do that without international cooperation.”
1. What is the new finding of scientists?| A．The east Antarctica is losing ice at an increasing rate. |
| B．The west Antarctica is melting six times faster than in 1979. |
| C．5 billion tons of ice is added to Antarctica each year. |
| D．The sea level has risen by 13.8 mm over the past 40 years. |
| A．A base mostly over sea level. | B．The force of gravity. |
| C．The invasion of a warm current. | D．Extremely low temperature. |
| A．Fragile. | B．Unattackable. |
| C．Mild. | D．Unstable. |
| A．Satellite imagery. | B．Global monitoring. |
| C．Worldwide climate modeling. | D．Worldwide combined efforts. |
5 . It is quite apparent that competition surrounds every aspect of human life whether in the United States or the Amazon rainforest. Without it we would not have grown into primates (灵长类动物) . Or we would probably still be struggling to sharpen a bronze tool while crawling around on four legs in search of meat. Without competition, Columbus wouldn’t have discovered America and Edison would never have invented the light bulb.
Friendship, like all relationships between two people, involves competition. It isn’t competition in a traditional sense because there are no goals to be scored and no prize. Perhaps the ecological definition --- the simultaneous (同时) demand by two or more organisms for limited environmental resources, such as nutrinents, living space, or light --- better explains it.
As in nature, high school life is governed by a set of laws, similar to a shortened version of Darwin’s theory of evolution, overpopulation, and competition. There is an abundance of high school students and to distinguish them, ranking and categorizing (分类) take place. In high school, friendships learn to coexist with competition even though at times the relationship is rough. In fact, in some circumstance, competition is too much of a burden for a friendship to bear, causing it to fall apart. College admission is the final high school objective. Four years of hard work is to achieve good grades, and a student’s fate is determined not only by these achievements, but by the records of thousands of other seniors trying to achieve a similar recognition.
Nevertheless, by necessity, competition between students exists in all aspects of high school life. It sets and improves the standards in everything from sports to schoolwork. A healthy, friendly competition can have only benefits, but when it becomes too fierce, jealousy (妒忌) can tear friendships apart. Yet, despite all this, without competition, we would be lost.
1. What does the ecological definition mainly explain?| A．How to win the competition. | B．What competition exactly is. |
| C．What the result of competition is. | D．How friends compete with each other. |
| A．They know the laws of nature well. | B．Friendship is a burden for them. |
| C．The number of them is too large. | D．They are divided into different groups. |
| A．Friendship is always based on competition. |
| B．Competition is a result of lost friendship. |
| C．Competition is terribly harmful to friendships. |
| D．The degree of competition is vital to friendship. |
| A．Competition is certain to happen at school. |
| B．The result of competition are out of control. |
| C．Competition becomes fierce in high school. |
| D．Friendship is not as important as competition at school. |
6 . We may think we're a culture that gets rid of our worn technology at the first sight of something shiny and new, but a new study shows that we keep using our old devices(装置) well after they go out of style. That’s bad news for the environment — and our wallets — as these outdated devices consume much more energy than the newer ones that do the same things.
To figure out how much power these devices are using, Callie Babbitt and her colleagues at the Rochester Institute of Technology in New York tracked the environmental costs for each product throughout its life — from when its minerals are mined to when we stop using the device. This method provided a readout for how home energy use has evolved since the early 1990s. Devices were grouped by generation — Desktop computers, basic mobile phones, and box-set TVs defined 1992. Digital cameras arrived on the scene in 1997. And MP3 players, smart phones, and LCD TVs entered homes in 2002, before tablets and e-readers showed up in 2007.
As we accumulated more devices, however, we didn't throw out our old ones. "The living-room television is replaced and gets planted in the kids' room, and suddenly one day, you have a TV in every room of the house," said one researcher. The average number of electronic devices rose from four per household in 1992 to 13 in 2007. We're not just keeping these old devices — we continue to use them. According to the analysis of Babbitt's team, old desktop monitors and box TVs with cathode ray tubes are the worst devices with their energy consumption and contribution to greenhouse gas emissions（排放）more than doubling during the 1992 to 2007 window.
So what's the solution（解决方案）? The team's data only went up to 2007, but the researchers also explored what would happen if consumers replaced old products with new electronics that serve more than one function, such as a tablet for word processing and TV viewing. They found that more on-demand entertainment viewing on tablets instead of TVs and desktop computers could cut energy consumption by 44%.
1. What does the author think of new devices?| A．They are environment-friendly. | B．They are no better than the old. |
| C．They cost more to use at home. | D．They go out of style quickly. |
| A．To reduce the cost of minerals. |
| B．To test the life cycle of a product. |
| C．To update consumers on new technology. |
| D．To find out electricity consumption of the devices. |
| A．The box-set TV. | B．The tablet. |
| C．The LCD TV. | D．The desktop computer. |
| A．Stop using them. | B．Take them apart. |
| C．Upgrade them. | D．Recycle them. |
7 . We’ve all been there: in a lift, in line at the bank or on an airplane, surrounded by people who are, like us, deeply focused on their smartphones or, worse, struggling with the uncomfortable silence.
What’s the problem? It’s possible that we all have compromised conversational intelligence. It’s more likely that none of us start a conversation because it’s awkward and challenging, or we think it’s annoying and unnecessary. But the next time you find yourself among strangers, consider that small talk is worth the trouble. Experts say it’s an invaluable social practice that results in big benefits.
Dismissing small talk as unimportant is easy, but we can’t forget that deep relationships wouldn’t
even exist if it weren’t for casual conversation. Small talk is the grease(润滑剂) for social communication, says Bernardo Carducci, director of the Shyness Research Institute at Indiana University Southeast. ＂Almost every great love story and each big business deal begins with small talk,＂ he explains. ＂The key to successful small talk is learning how to connect with others, not just communicate with them.＂
In a 2014 study, Elizabeth Dunn, associate professor of psychology at UBC, invited people on their way into a coffee shop. One group was asked to seek out an interaction(互动) with its waiter; the other, to speak only when necessary. The results showed that those who chatted with their server reported significantly higher positive feelings and a better coffee shop experience. ＂It’s not that talking to the waiter is better than talking to your husband,＂ says Dunn. ＂But interactions with peripheral(边缘的) members of our social network matter for our well-being also.＂
Dunn believes that people who reach out to strangers feel a significantly greater sense of belonging, a bond with others. Carducci believes developing such a sense of belonging starts with small talk. ＂Small talk is the basis of good manners,＂ he says.
1. What phenomenon is described in the first paragraph?| A．Addiction to smartphones. |
| B．Inappropriate behaviours in public places. |
| C．Absence of communication between strangers. |
| D．Impatience with slow service. |
| A．Showing good manners. | B．Relating to other people. |
| C．Focusing on a topic. | D．Making business deals. |
| A．It improves family relationships. | B．It raises people’s confidence. |
| C．It matters as much as a formal talk. | D．It makes people feel good. |
| A．Conversation Counts | B．Ways of Making Small Talk |
| C．Benefits of Small Talk | D．Uncomfortable Silence |
