1 . The scientists who re-engineered the plastic-eating enzyme(酶) PETase have now created a new enzyme called “cocktail” , which can digest plastic up to six times faster.
PETase breaks down PET back into its building blocks, creating an opportunity to recycle plastic and reduce plastic pollution. PET is the most common thermoplastic(热塑性塑料) used to make single-use drinks bottles, which takes hundreds of years to break down in the environment, but PETase can shorten this time to days. The initial discovery set up the prospect of a revolution in plastic recycling, creating a potential low-energy solution to tackle plastic waste.
Now, the same trans-Atlantic team have combined PETase and its “partner”, a second enzyme called MHETase, to generate much bigger improvements: simply mixing PETase with MHETase doubled the speed of PET breakdown, and engineering a connection between the two enzymes to create a “super-enzyme”, increased this activity by a further three times.
The team was co-led by the scientists who engineered PETase, Professor John McGeehan and Dr Gregg Beckham. Professor McGeehan said: “Gregg and I were chatting about how PETase attacks the surface of the plastics and MHETase chops things up further, so it seemed natural to see if we could use them together. Our first experiments showed that they did work better together, so we decided to physically link them. It took a great deal of work, but it was worth the effort — we were delighted to see that our new enzyme is up to three times faster than the separate enzymes.”
The original PETase enzyme discovery indicated the first hope that a solution to the global plastic pollution problem might be within grasp, though PETase alone is not yet fast enough to handle the tons of PET bottles. Combining it with a second enzyme, and finding together they work even faster, means another leap forward has been taken towards finding a solution to plastic waste. PETase and the new combined MHETase-PETase both work by digesting PET plastic. This allows for plastics to be made and reused endlessly, reducing our reliance on fossil(化石) resources.
1. What can we learn about “cocktail” from the text?| A．It doubles the breakdown of plastics. |
| B．It takes hundreds of years to break down. |
| C．It contributes to breaking down plastic quickly. |
| D．It deals with the plastic waste three times faster. |
| A．A new study of PET. | B．The breakdown of PET. |
| C．The discovery of PETase. | D．The functions of PETase. |
| A．Co-leading the trans-Atlantic team. | B．Combining PETase and MHETase. |
| C．Attacking the surface of the plastics. | D．Talking about conducting experiments. |
| A．PET pollution is no longer a difficult problem to deal with. |
| B．New enzyme is speeding up our reliance on fossil resources. |
| C．MHETase-PETase makes the world free from plastic pollution. |
| D．Plastic-eating enzyme “cocktail” promises new hope for plastic waste. |
2 . Dubai is the commercial capital of the oil-rich United Arab Emirates in the Persian Gulf. But officials want to turn it into the world’s “smartest” city. Earlier this year, Dubai announced plans to be the world’s first city to use self-driving taxis. In June, it placed the first robot police officer at shopping centers and places popular with visitors. Dubai police officials now say they plan to use self-driving vehicles to patrol (巡逻) city streets by the end of the year.
Dubai will be the first in the world to use the O-R3 vehicle, according to the Singapore company that builds it. The company, OTSAW Digital, recently signed an agreement with the Dubai Police force to supply the driverless robots.
The vehicles look a lot like most other automobiles, but are much smaller. They are equipped with cameras, machine learning tools and 3D technology to help them operate independently. The robots automatically charge themselves when power gets low.
The vehicle’s cameras can scan faces and record registration information to check for criminals and possible illegal activities. A police official said the robot can recognize people in any area. It will be used to “identify suspicious objects and follow suspects.” “We seek to increase operations with the help of technology such as robots,” said Dubai’s police chief. “We always search for the best technology to serve our police work for a safer and smarter city.”
The O-R3 can communicate with computers at police centers in different locations. The patrolling robot is able to send data and video to the centers, where operators can control the vehicle remotely. The vehicles can also work together with drones (无人机) that can be launched from the back of the robot. The drones can then follow the vehicles and provide more support from the air.
The CEO of OTSAW Digital, Ting Ming Ling, says the use of such vehicles is designed to help humans with their jobs, not replace them. “Eventually, robots exist to improve the quality of human lives, where men take on high value jobs while robots perform the low skilled ones,” he said.
1. What does the underlined word “them” in paragraph 3 refer to?| A．Learning tools. | B．O-R3 vehicles. |
| C．Common automobiles. | D．3D cameras. |
| A．To take the place of the work of human beings. |
| B．To gather information of faces in the streets. |
| C．To help investigate criminal activities more effectively. |
| D．To keep an eye on people’s behaviors in the city. |
| A．Gather more information for O-R3 vehicle. |
| B．Protect the vehicle from the sky. |
| C．Show directions for the vehicle. |
| D．Control the vehicle remotely. |
| A．Police in Dubai Have the Most Advantaged Equipment |
| B．Dubai Will Put Self-Driving Police Vehicles on Streets |
| C．You Will Not See Police Officers in the Streets of Dubai |
| D．Robot Police Officers Are Much Smarter than Human Ones |
3 . Eyes are like a window into our thought processes. Recent studies have found that the eyes not only reflect what is happening in the brain but may also influence how we remember things.
Researchers tracked volunteers' eye movements while they said a list of 40 numbers. They found that the direction and size of the participants’ eye movements accurately predicted whether the number they were about to say was bigger or smaller than the previous one and by how much. Each volunteers’ gaze shifted up and to the right just before they said a bigger number, and down and to the left before a smaller one. The bigger the shift from one side to the other, the bigger the difference between the numbers.
This suggests that we somehow link abstract number representations in the brain with movement in space. But the study does not tell us which come first : whether thinking of a particular number causes changes in eye position, or whether the eye position influences our mental-activity. Researchers in Sweden published evidence that it's the latter that may be at work : eye movements may actually facilitate memory retrieval.
They asked each one of the 24 volunteers to carefully examine a series of objects displayed to them in one corner of a computer screen. The participants were then told to listen to a series of statements about some of the objects they had seen, such as "The car was facing to the left" and asked to indicate as quickly as possible if each was true or false. Some participants were allowed to let their eyes move about freely; others were asked to fix their gaze on a cross at the centre of the screen, or the corner where the object had appeared, for example.
The researchers found that those who were allowed to move their eyes freely during recall performed significantly better than those who fixed on the cross. Interestingly, though, participants who were told to fix their gaze in the corner of the screen in which objects had appeared earlier performed better than those told to fix their gaze in another corner. This suggests that the more closely the participants eye movements during information encoding corresponded withthosethat occurred during retrieval of the information, the better they were at remembering the objects.
1. If the previous number was 50, which is the most probable number when a participant looked up and right?| A．90 | B．50 | C．40 | D．30 |
| A．The way that eye movements take place. |
| B．The way that memory retrieval takes place. |
| C．The relationship between eye movements and numbers. |
| D．The relationship, between eye movements and mental activity. |
| A．The objects. | B．The corners. |
| C．The participants. | D．The eye movements. |
| A．To find ways to improve a person's memory. |
| B．To test the influence of eye movements on memory. |
| C．To test the effects of different eye movements. |
| D．To see how eye movements help to identify objects. |
4 . Thirst is one of the fundamental urges a living thing can have. After all, water is the solvent that we rely on to transport essential molecules (分子) around our bodies to keep us alive. So it is perhaps a bit suspicious that water doesn’t seem to have any flavor. Shouldn’t we have evolved a taste for this essential substance?
Well, perhaps we have. Several new studies seem to indicate not only that water does, in fact, have a taste, but that we might have taste buds (味蕾) that respond directly to it.
We now know that there are at least five basic tastes: salty, sour, sweet, bitter and umami. If there is a sixth taste for water, then we should be able to see evidence for it somewhere in the mouth or tongue. Yuki Oka and his colleagues have sought to solve the issue once and for all. They have thought up an experiment that seeks to identify any water sensing taste receptor cells (TRCs) on the tongues of lab mice.
The team first used a technique known as genetic knockout to silence different types of TRCs, in order to remove the possibility that those cells might accidentally discover some other taste within the water besides the water itself. They then flushed the rodents’ mouths with water to see if any cells were still responding. It turned out that the acid-sensing sour TRCs were still firing vigorously indicating these cells might have a double purpose, capable of distinguishing water or acidic fluids.
So if you are on the side of the debate that argues that water is flavorless, you might still be correct. But water isn’t senseless. At least it doesn’t appear that way according to this research. The study also opens up the possibility that our tongues and taste buds might be doing more than merely providing us with a sense of taste. If this study doesn’t prove that water is the sixth flavor, it might nonetheless be the first evidence of a whole other sense entirely: a water sense.
1. Why is the question asked in the first paragraph?| A．To introduce the main topic. |
| B．To show ordinary people’s puzzlement. |
| C．To express the writer’s curiosity. |
| D．To explain the reason for suspicion. |
| A．Researchers. | B．Yuki oka’s colleagues. |
| C．Thirsty people | D．Mice. |
| A．to create some cells | B．to remove some cells |
| C．to identify some certain cells | D．to disable some cells |
| A．Water is flavors without doubt. |
| B．Water is the sixth flavor. |
| C．Water can be sensed. |
| D．Water can attack TRCs. |
5 . We can achieve knowledge either actively or passively. We achieve it actively by direct experience, by testing and proving an idea, or by reasoning.
We achieve knowledge passively by being told by someone else. Most of the learning that takes place in the classroom and the kind that happens when we watch TV or read newspapers or magazines is passive. Conditioned as we are to passive learning, it's not surprising that we depend on it in our everyday communication with friends and co-workers.
Unfortunately, passive learning has a serious problem. It makes us tend to accept what we are told even when it is little more than hearsay (传间) and rumor.
Did you ever play the game Rumor? It begins when one person writes down a message but doesn't show it to anyone. Then the person whispers it, word for word, to another person. That person, in turn, whispers it to still another, and so on, through all the people playing the game. The last person writes down the message word for word as he or she hears it. Then the two written statements are compared. Typically, the original message has changed.
That's what happens in daily life. The simple fact that people repeat a story in their own words changes the story. Then, too, most people listen imperfectly. And many enjoy adding their own creative touch to a story, trying to improve on it, stamping it with their own personal style. Yet those who hear it think they know.
This process is also found among scholars and authors: a statement of opinions by one writer may be restated as the fact by another, who may in turn be quoted by yet another; and this process may continue, unless it occurs to someone to question the facts on which the original writer based his opinion or to challenge the interpretation he placed upon those facts.
1. Which of the following will help us achieve active learning?| A．Reading scientific journals. |
| B．Listening to the teacher in class. |
| C．Doing a chemical experiment. |
| D．Watching news programs on TV. |
| A．Knowledge. | B．Newspaper. |
| C．Active learning. | D．Passive learning. |
| A．Playing games can make people more active. |
| B．A message may be changed when being passed on. |
| C．People tend to like telling lies when playing games. |
| D．People may have problems with their sense of hearing.. |
| A．Passive learning may not be reliable. |
| B．Active learning is much more important. |
| C．Active learning occurs more frequently. |
| D．Passive learning is not found among scholars. |
6 . Over 400 human footprints preserved in volcanic sediment （沉淀物）provide a sign at social life among ancient hunter-gatherers. The impressions, found in northern Tanzania, add up to Africa's largest collection of ancient human footprints, say evolutionary biologist Kevin Hatala of Chatham University in Pittsburgh and colleagues. People walked across a muddy layer of volcanic ashes dating to between 19,100 and 5,760 years ago, the researchers reported on May 14 in Scientific Reports. Dating of a thin rock layer that partly overlaps （重 叠）the sediment narrows the footprints' age to about 12,000 to 10,000 years ago.
Hatala's team analyzed footprint sizes, distances between prints and which way prints pointed. One collection of tracks was made by 17 people walking southwest. Comparisons with modern prints suggest that this group consisted of fourteen women, two men and one young boy. The women may have been searching for foods while a few males visited or accompanied them, the researchers infer. Some present-day hunter-gatherers form lately female food-gathering groups.
The study is "a nice piece of work”, although it's hard to specify what people were doing, says geologist Matthew Bennett of Bournemouth University in Poole, England.
Many more sets of footprint tracks would be needed to argue convincingly that hunter-gatherers at that time had female food-gathering groups, Bennett says. And it would still be unknown if the women were gathering plants or hunting prey. Other footprint sites present especially promising opportunities for studying ancient behavior, he says. He is involved in work in New Mexico that has uncovered tens of thousands of footprints of humans and other creatures from more than 10,000 years ago. Early results suggest that humans there hunted giant sloths （树 獭）.Bennett expects those prints will yield more insights into Stone Age hunting.
1. What does the underlined word "impressions” in the first paragraph mean?| A．Thoughts about people or things. | B．Collections of volcanic ashes. |
| C．Marks left by creatures or something. | D．Behaviors of imitating someone- |
| A．Ancient hunters were socially organized. |
| B．Ancient male hunters were admired by females. |
| C．Female food-gathering groups were obviously formed. |
| D．Males played a more important role in finding food than females. |
| A．The females gathered plants or hunted prey in the Stone Age. |
| B．The footprint tracks have proved female food-gathering groups existed. |
| C．The footprint sites provide a good chance to further study ancient behavior |
| D．The footprints will hardly influence our understanding of Stone Age hunting. |
| A．How Ancient Hunters Gathered Food |
| B．What Ancient Hunan Footprints Were Like |
| C．What Ancient Human Footprints Tell Us |
| D．How Ancient Food-Gathering Groups Cooperated |
7 . Having a microchip implanted in a man's brain may be common in sci-fi movie plots, but it may soon become an actual possibility.
Elon Musk -a US tech tycoon, founder of Space X- has been working on this technology. On Aug 28, Musk gave a display of the chip, which was implanted into the head of a pig named Gertrude.
The chip, developed by Musk's company Neuralink, is the size of a coin. But don't let its size fool you. The tiny chip has over 3,000 electrodes （电极）attached to flexible threads, which can monitor about 1,000 neurons （神经元）.It collects neural signals from an area of the brain, and then transmits those signals wirelessly to nearby computers, according to MSN. That enabled researchers to monitor Gertrude's brain activity while she was walking around in the display.
Though the technology is still in its early stage, it is encouraging for humans. This technology would solve a lot of brain injuries and is essentia] for Al symbiosis, which will allow the human brain to combine with an artificial intelligence.
When the device can be applied to humans, its main goal will be to help those who have mobility difficulties. Musk hopes this technology can also be used to help those with hearing and eyesight issues.
Although such a device could repair those problems, putting it into practice is by no means a piece of cake. Currently, the device can transmit signals from about 500 neurons in the pig's brain. Compared to 80 billion neurons in a human brain, this number is tiny. And to cover the whole human brain also means the electrodes have to be much smaller.
Also, implanting the chip into the brain poses a potential danger. There is a risk of the immune system attacking this foreign body.
Right now, the hope of controlling the brain via controlling a few neurons seems overly optimistic. "There are many technological challenges ... to overcome before Neuralink can put its devices to the purposes," Yuan Lanfeng, an associate professor at the University of Science and Technology of China, told China Daily.
1. What do we know about Elon Musk's microchip?| A．It was inspired by sci-fi movie plots. |
| B．It is able to collect wireless signals. |
| C．It is tiny in size but powerful in function. |
| D．It has been implanted into a human's brain. |
| A．The operation of the chip in Gertrude’s brain. |
| B．The attachment of electrodes to flexible threads. |
| C．The development of neurons inside Gertrude's brain. |
| D．The transmission of signals from a nearby computer |
| A．To monitor animals’ brain activity. |
| B．To help people with mobility issues. |
| C．To develop a cure for immune system problems. |
| D．To contribute to the research on Al technologies. |
| A．Worried. | B．Excited. | C．Optimistic. | D．Challenged. |
8 . When we learn to drive, we need to learn basic skills such as how to switch on the engine, turn on the wipers, operate the brakes, etc. before we actually take to the road. Once the lower order operations and skills listed above have been automatized or at least routinized to the extent that we do not have to pay attention to them (by-pass Working Memory's attentional systems), we can actually be safe in the assumption that we can wholly focus on the higher order skills which will allow us to take the split seconds decisions that will prevent us from getting lost, clash with other cars, break the traffic laws while dealing with our children messing about in the back seats.
This is what the brain does, too, when learning languages. Because Working Memory has a very limited space available when performing any task, the brain has learnt to automatize lower order skills so that, by being performed “subconsciously' they free up cognitive(认知）space.So, for instance, if I am an advanced speaker who has routinized accurate pronunciation, grammar and syntax to a fairly high degree, I will be able to devote more conscious attention (Working Memory space) to the message I want to put across. On the other hand, if I still struggle with pronunciation, word order, irregular verb forms and tenses most of my attention will be taken up by the mechanics of what I want to say, rather than the meaning; this will slow me down and limit my ability to think through what I want to say due to cognitive overload.
In language teaching this important principle translates as follows: in order to enable our students to focus on the higher order skills involved in comprehension and production we need to ensure that the lower-order ones have been acquired or performance will be reduced.
1. What does paragraph 1 mainly tell us?| A．We should improve our driving skills on the road. |
| B．Our basic driving will be better as time goes on and on. |
| C．Only by mastering driving skills can we drive safely. |
| D．We must operate automatically when driving on the roads. |
| A．Learning languages has specific characters. |
| B．Skillful driving benefits language learning. |
| C．Driving safely is harder than language learning. |
| D．Driving and language learning share similar skills. |
| A．The meaning we want to express. |
| B．Struggle with language learning problems. |
| C．Spending more time on the topic. |
| D．Devoting more conscious attention. |
| A．Well begun,half done. |
| B．It is never too old to learn. |
| C．Practice makes perfect. |
| D．Learn to walk before you run. |
9 . Parks in cities are usually considered as islands of green among seas of concrete and steel. When you approach the High Line on the west side of Manhattan, what you see first is the kind of thing urban parks were created to get away from—a heavy, black steal structure supporting a raised rail line that once brought freight(货运)trains right into factories, and that looks, at least from a distance, more like some abandoned leftover from the past than an urban oasis(绿洲).
That is what the High Line was until recently. But now, it has been turned into one of the most inviting public spaces. The black steel columns now hold up a raised park. Walking on the High Line, you float about eight meters above the ground. You can sit surrounded by carefully tended plantings and take in the sun and the Hudson River views, or you can walk the line as it winds its way between old buildings and striking new ones. I have walked the High Line dozens of times. Different from any street, sidewalk, or park, it never fails to surprise and delight me. The most extraordinary thing about the High Line is the way without streets to cross or traffic lights to wait for, ten blocks pass as quickly as two.
The High Line is a dream come true. The real heroes of the story are Joshua David and Robert Hammond. “I saw an article saying that the High Line was to be destroyed, and I wondered if anyone wanted to save it,” Hammond said. “I saw that it was on the agenda for a community meeting. I went to see what was going on, and there I met David. We were the only people there who wanted to save it.”
“The railroad representatives showed some plans to reuse it, which enraged(激怒)the people who were trying to get it torn down. We couldn’t believe the degree of rage those people had. Hammond and I asked railroad officials to take them to look at the High Line. When we got up there, we saw a mile and a half of wildflowers. New Yorkers always dream of finding open spaces—it’s fantasy when you live in a studio apartment.” David said. And that’s how the project began.
1. What does the underlined word “That” in Paragraph 2 refer to?| A．An urban oasis. | B．A raised rail |
| C．A black steel structure. | D．An abandoned leftover. |
| A．He can always see strange things. |
| B．The weather seems much better there. |
| C．New buildings keep being built around it. |
| D．He can cover more miles in the same amount of time. |
| A．Because he was the representative of the railroad. |
| B．Because he went there to accompany his friend David. |
| C．Because he wanted to see if others would share his views. |
| D．Because he thought he could persuade people to join in his campaign. |
| A．He was pleased to realize he might succeed. |
| B．He was encouraged by everyone’s determination. |
| C．He was worried that their way of life might change. |
| D．He was surprised by the reactions to the idea proposed. |
10 . The eastern Siberian landscape is not normally like hell. In winter it is blanketed in snow:in summer, its forests are lush(苍翠繁茂的). This year, however, the region is on fire, as one large parts of the Arctic Circle.
The fires began in June, caused by an extremely hot and dry early summer. It was the hottest June on record globally. In the regions that are burning, temperatures peaked at 8-10℃ warmer than the average from 1981 to 2010. This has dried out the landscape, producing tinder(易燃物)for natural forest fires.
So far, hundreds of above-ground fires have been recorded by satellites in the Arctic and sub-Arctic. It is estimated that fires within the Arctic Circle have produced more than 100m tonnes of carbon dioxide in a year. That is a lot. But burnt vegetation can regrow within a decade, and in doing so reabsorbs much of the released carbon dioxide. It is what is happening below ground that most worries ecologists and climate scientists.
Global warming will melt Arctic permafrost(永久冻土), releasing large amounts of stored greenhouse gases. But if fires in the region become more common, that could have even bigger consequences. Wildfires will release much faster and bigger amounts of carbon, rather than melting permafrost. The fires also produce black carbon which, if dropped on the Arctic sea ice by favourable winds, will darken its surface, making it more likely to absorb sunlight and melt. This decreases the reflectivity of the region and further increases Arctic warming.
Smog from the fires is blanketing much of Siberia. "What is scary about the Arctic fires is that they are driven by climate change, and there's very little you can do," says Thomas Smith. Few natural fires this big have ever been successfully managed. The only way to deal with the spread of these fires is to slow the rate of global warming. Don't hold your breath.
1. What do we know about the wild fires in the Arctic Circle?| A．They are common yearly phenomena. | B．They come earlier than usual this year. |
| C．They result from extreme weather. | D．They destroy Siberian landscape. |
| A．Hundreds of above-ground fires. | B．100m tonnes of carbon dioxide. |
| C．Burnt plant life within a decade. | D．Satellite distribution in the Arctic. |
| A．The causes of fires. | B．The consequences of fires. |
| C．The working principles of global warming. | D．The characteristics of Arctic warming. |
| A．Objective. | B．Indifferent. | C．Optimistic. | D．Worried. |
