1 . It’s hard to turn down hamburgers, French fries, potato chips and all of the other junk food that seem to call out to us. However, eating too much junk food can harm your body, particularly if you’re between the ages of 10 and 19.
“Junk food shapes adolescent brains in ways that impair (损害) their ability to think, learn and remember. It can also make it harder to control impulsive (冲动的) behaviors, said Amy Reichelt, a brain and nutrition specialist at Western University, Canada. “It may even increase a teen’s risk of depression and anxiety.”
Reichelt and two other researchers reviewed more than 100 studies, including their own, about how poor food choices can impact adolescent brains. They found adolescents are more sensitive than any other age group to processed foods with a lot of fat and sugar as their brains are not yet fully formed.
Adolescent brains are still developing the ability to assess risks and control actions. The prefrontal cortex (前额皮质) is the part of the brain that tells us we shouldn’t eat chips all the time and helps us resist that urge. However, this region is the last to mature — it doesn’t fully develop until we are in our early 20s.
Meanwhile, teen brains get more buzz (兴奋) from rewards. The parts of the brain that make us feel good when we do something pleasurable — like eating tasty foods — are fully developed by the teen years.
In fact, these regions are even more sensitive when we are young. That’s because dopamine (多巴胺), a natural chemical that lifts our mood when we experience something good, is especially active in adolescent brains.
Therefore, the teen brain has two strikes against it when it comes to resisting junk food. “It has a heightened drive for rewards and reduced self-regulation,” said Reichelt.
Reichelt and her team conducted their own study using mice, whose brains develop much like our own. They discovered that the “teenage” mice that had a high-fat diet performed worse on memory tests than those eating a normal diet. Researchers said the high-fat diet may make the mice’s prefrontal cortex work less effectively.
So, what’s the best way to say no to junk food? Researchers suggest exercise. When we exercise, the brain’s reward system becomes less sensitive to food cues (线索). Exercise also triggers the body to make a protein that helps brain cells grow and boosts connections between the prefrontal cortex and other brain regions. The prefrontal cortex thus can work better to help us make wise decisions and control our impulses.
1. What is the purpose of the first two paragraphs?| A．To figure out what junk food is. |
| B．To explain the dangers of junk food. |
| C．To show how junk food affect the brain. |
| D．To analyze why junk food is hard to resist. |
| A．Processed food makes them sensitive. |
| B．It is hard to control impulsive behaviors. |
| C．Their still-developing prefrontal cortex. |
| D．The low level of dopamine in their brains. |
| A．Our mood could suffer from eating junk food. |
| B．High-fat diets may negatively affect our creativity. |
| C．The brain of a mouse is similar to that of a person’s. |
| D．High-fat diets can harm our ability to process information. |
| A．It reduces the desire for junk food. |
| B．It activates the brain’s reward system. |
| C．It helps the prefrontal cortex work better with dopamine. |
| D．It makes the body produce a protein that controls our impulses. |
| A．Fashion. | B．Technology. | C．Health. | D．Entertainment. |
2 . People who grow up outside of cities are better at finding their way around than urbanites, a large study on navigation suggests. The results, described online on March 30 in Nature, hint that learning to handle environmental complexity as a child strengthens mental muscles for spatial skills.
Nearly 400,000 people from 38 countries around the world played a video game called Sea Hero Quest, designed by scientists and game developers as a fun way to collect data about people’s brains. Players piloted a boat in search of various targets.
On average, people who said they had grown up outside of cities, where they would have probably encountered lots of complicated paths, were better at finding the targets than people who were raised in cities.
What’s more, the difference between city residents and outsiders was most obvious in countries where cities tend to have simple layouts (布局), such as Chicago with its streets laid out at 90-degree angles. The simpler the cities, the bigger the advantage for people from more rural areas, cognitive scientist Antoine Coutrot of CNRS and his colleagues report.
Still, from these video game data, scientists can’t definitively say that the childhood environment is behind the differences in navigation. But it’s possible. “As a kid, if you are exposed to a complex environment, you learn to find your way, and you develop the right cognitive processes to do so,” Coutrot says.
Other factors have been linked to navigational performance, including age, gender, education and even a superior sense of smell. Figuring out these details will give doctors a more precise baseline (基准) of a person’s navigational abilities. That, in turn, might help reveal when these skills weaken, as they do in early Alzheimer’s disease, for instance.
1. What does the underlined word “urbanites” in Paragraph 1 refer to?| A．Those who live close to urban areas. |
| B．Those who are from rural areas. |
| C．Those who are raised in cities. |
| D．Those who long for urban life. |
| A．By playing a game called Sea Hero Quest. |
| B．By gathering data from the video game. |
| C．By recording electrical activities in brains. |
| D．By comparing various targets of the game. |
| A．City outsiders performed no better than city residents in the study. |
| B．Cities’ simple layouts gave city residents an advantage in the game. |
| C．There was no significant difference between city residents and outsiders. |
| D．The players’ performance had something to do with their earlier experience. |
| A．Childhood surroundings might affect people’s navigational abilities. |
| B．Gender and education are key to developing navigational abilities. |
| C．A superior sense of smell bears no relation to navigational abilities. |
| D．The study of navigational abilities can help cure Alzheimer’s disease. |
| A．How environment impacts early childhood development |
| B．Why is early childhood education important for our future |
| C．When is the best time to obtain your navigational skills |
| D．Where you grew up may shape your navigational skills |
3 . Expertise (专门技能) is what separates amateurs from true masters in almost any field. You might wonder whether experts are “born” or “made”. Experts in the field prove that expertise is acquired through dedicated practice, but how exactly people go about becoming experts?
People who become experts tend to get a body of knowledge that makes them one of the most knowledgeable individuals in their field. They also possess the skills that they need to determine when and how to use their knowledge. Recently, a popular idea has emerged that the key to becoming an expert is devoting at least 10,000 hours to the study and practice of a subject. Pop psychology author Malcolm Gladwell created the phrase “the ten-thousand-hour rule”. Gladwell also suggested tech-entrepreneur Bill Gates had devoted 10,000 hours to practicing programming before he created Microsoft.
Anders Ericsson of the University of Florida, who is a famous expert, has studied the experts from all walks of life and points out deficiency of “the ten-thousand-hour rule”. Ericsson believes that what separates the amateur from experts is what is referred to as deliberate practice. Ordinary practice can help people become skilled at a task, but such practice involves working on things that are outside of their current skill-level, setting goals, and receiving training and instruction from a qualified teacher.
While Ericsson believes deliberate practice is the key to becoming an expert, not all researchers agree with his conclusion. Some recent studies have found deliberate practice isn’t the only factor that explains the differences between the skilled and the unskilled. While psychologists aren’t sure exactly which factors might also play a role, personality traits, physical characteristics, and overall intelligence may matter as well.
Practice is essential for developing a skill, but becoming an expert requires constantly challenging yourself to do better, learn more, and acquire new knowledge and skills. Simply practicing the same skills over and over again will make you better in those areas, but it won’t lead to true experts.
1. What can we know about experts?| A．They are able to apply knowledge flexibly and properly. |
| B．They have a good command of knowledge of other fields. |
| C．They are born with the ability to master professional skills. |
| D．They acquire expertise through the development of individuality. |
| A．To prove his “the ten-thousand-hour rule”. |
| B．To show 10,000 hours’ devotion could create Microsoft. |
| C．To prove becoming experts has little to do with personal skills. |
| D．To show the importance of researching various subjects at the same time. |
| A．Influence. | B．Uncertainty. | C．Significance | D．Disadvantage. |
| A．They think deliberate practice is not reasonable. |
| B．They think he fails to provide a basis for his opinion. |
| C．They place greater emphasis on the psychological level. |
| D．They think he might ignore other aspects of being an expert. |
| A．Practice should be carried on within one’s familiar skill-level. |
| B．Constant improvement of learning skills can lead to true expertise. |
| C．Being an expert is more than the result of practising the same skills. |
| D．Ordinary practice is the most important condition for being an expert. |
| A．become a true expert | B．take advantage of new skills |
| C．acquire new knowledge and skills | D．tell a “born” expert from a “made” expert |
4 . Placing large-scale renewable energy equipment is difficult and often met with criticism, especially in areas where landscape of the area is considered a cultural heritage(遗产) or is a tourist spot which brings in good income. Therefore, the human interaction is kept at a minimal rate to avoid damaging the environment.
Changes in biodiversity due to equipment of solar energy and wind power is thought to be more damaging than overall reduction in greenhouse gasses. This is one of the reasons why acquiring land for renewable energy equipment is so difficult, since traditional uses of land such as agriculture are preferred more than placing power plants. However, recent research shows that installing such renewable equipment actually promotes biodiversity.
Now a comprehensive research has been carried out on ‘The Effects of Solar Farms on Local Biodiversity‘ in UK by ecological consultants who proved these theories. The consultants studied 11 similar solar farms located around England and Wales along with their neighboring control farms to compare. Plants (crops), invertebrate(无脊椎动物), bird and bat surveys were carried out on both the farms. One test before solar arrays were set up on the land and then after.
The results of the study exceptionally proved that solar farms had significantly higher biodiversity than the control farms. The solar farm had by far the most positive effect on biodiversity when the farmland was replanted with a mixture of different seeds after the solar farm was constructed. This minimized use of agricultural chemicals and promoted marginal habitat space for other species.
The report further went on to say that reduction in greenhouse gas emissions was just one of the positive effects.
The other one was that the increase in wildlife and biodiversity inside the solar farms actually extended to areas surrounding the solar farm as well. Construction has always come with a downside of damage to the local ecosystems, but since building solar farms actually benefit the wildlife, there couldn’t be better news to hear! A good reason of improved biodiversity would be the fact that farm is shifted from monoculture farming to a variety of crops. The limited use of pesticides and herbicides contributes to safer practices. Moreover, the presence of solar equipment provides shade for birds to make their nests (be kind to animals).
1. What do most people think of renewable energy equipment?| A．It’s too expensive. |
| B．It may turn a tourist spot. |
| C．It will do damage to the land. |
| D．It can serve as a cultural heritage. |
| A．Developing power plants. |
| B．Obtaining enough farmland. |
| C．Collecting enough funding. |
| D．Producing enough equipment. |
| A．It is the first study in this field. |
| B．Its result is beyond expectation. |
| C．It suggested canceling solar farms. |
| D．It needed further study. |
| A．People are Going Wild for Solar. |
| B．Solar Power Is Starting to Take off. |
| C．Solar Energy Will Be in Urgent Need. |
| D．Solar Farms Help Increase Biodiversity. |
5 . Fire ants are famous for their construction projects (as well as their burning bites). When they need to, colonies of these insects turn themselves into ladders, chains and walls. And when flood water rises, a colony can float to safety by making an unusual boat. The ants hold tightly to each other, forming a floating disk atop the water. The antraft may float for months seeking safe harbor. The ants on the bottom don’t drown, and the ants on the top stay dry. Working together, the ants float to safety — even though a single ant alone in the water will struggle to survive.
“They have to stay together as a colony to survive.” Nathan Mlot said.
Fire ants and water don’t mix. The ant’s hard outer shell, naturally repels water. A drop of water can sit on top of the ant like a backpack. When an ant does end up underwater, tiny hairs on its body can trap bubbles of air that give the bug a boost up.
To investigate the science behind the antraft, the scientists placed hundreds or thousands of ants at a time in the water. A group of ants took about 100 seconds, on average, to build a raft. The researchers repeated the experiment multiple times. Each time, the ants organized themselves the same way, creating a raft about the size and the thickness of a thin pancake. The rafts were flexible and strong, staying together even when the researchers pushed the rafts underwater.
The scientists then froze the rafts in liquid nitrogen and studied them under powerful microscopes to figure out how the ants kept everyone safe and the water out.
The team found that some ants used their jaws to bite other ants’ legs. Other ants joined their legs together. Thanks to these tight bonds, say the scientists, the ants did a better job at keeping the water away than any one ant could do on its own. By working together, thousands of ants can stay alive in the face of a crisis like a flood by using their own bodies to build a boat.
1. When flood comes, fire ants ________.| A．will run away separately | B．find a hole to hide themselves |
| C．combine themselves into a raft | D．climb onto boats on the water |
| A．Tiny hairs on their body. | B．Their hard outer shell. |
| C．Their slippery skin. | D．Their backpack on its body top. |
| A．built a raft in 100 minutes | B．organized themselves into a flexible raft |
| C．organized themselves in different ways | D．liked to look for the food of pancakes |
| A．practice | B．calmness | C．cooperation | D．speed |
| A．how fire ants react in face of danger | B．fire ants’ differences from common ants |
| C．fire ants’ ability to live underwater | D．the building ability of fire ants |
6 . While working as a graduate student in New York City, Vanessa Bohns was given the much
Was it possible, she wondered, that most of us are
Knowing this can help us understand how our requests might
| A．appealing | B．exhausting | C．sensitive | D．ashamed |
| A．glared | B．approached | C．passed | D．pushed |
| A．sympathetic | B．glad | C．annoyed | D．tolerant |
| A．upset | B．anxious | C．hesitant | D．willing |
| A．expected | B．requested | C．promised | D．recognized |
| A．curious | B．skeptical | C．wrong | D．cautious |
| A．discovered | B．conducted | C．planned | D．recorded |
| A．case | B．circumstance | C．occasion | D．condition |
| A．ignore | B．complain | C．refuse | D．cooperate |
| A．On the contrary | B．On the whole | C．On the surface | D．On the go |
| A．optimistic | B．critical | C．negative | D．neutral |
| A．strange | B．great | C．disappointing | D．normal |
| A．deny | B．doubt | C．appreciate | D．subscribe |
| A．misuse | B．overstate | C．distinguish | D．underestimate |
| A．imitate | B．practise | C．measure | D．perform |
| A．agree | B．fail | C．claim | D．pretend |
| A．angry | B．familiar | C．happy | D．uncomfortable |
| A．mislead | B．impress | C．affect | D．puzzle |
| A．accurately | B．accordingly | C．smoothly | D．systematically |
| A．boundaries | B．assumptions | C．defence | D．intention |
7 . It is generally believed that we are getting cleaned when we step under a shower. We are, but we’re also giving a home to lots of tiny little creatures we didn’t even know about. A showerhead carries thousands of bacteria called Mycobacterium (分支杆菌). These can cause problems like coughs and tiredness, and a general feeling of poorliness (身体不舒服). When you turn on the water, the bacteria go from the showerhead onto and into your body.
This is a finding of Norman R. Pace and his team at the University of Colorado, in the US. The scientists investigated bacteria in all kinds of human environment, including showers. Pace’s team looked at 45 showerheads in nine American cities. They discovered that 30 percent of them had large amounts of flying Mycobacterium.
But Pace said that they pose few threats to the health. Only those with a weak immune system might need to worry. He told the New York Times that the bacteria are not as unpleasant as might be thought. He said that having a shower is no more dangerous than anything else we do in the morning.
But for those who feel sick about the idea of all those microorganisms (微生物), he had some advice. Let the water run for 30 seconds before getting into the shower. Why? The number of bacteria is smaller than that when the water is just turned on. If that seems like a waste of water, he added that you could also change your showerhead every few months.
However, Pace had good news too. He has also been testing the air in US subways. Apart from iron particles (粒子), which are ground off the track by the wheels of trains, subway air is fresh. The reason is that a train’s movement pumps fresh outdoor air into the tunnels.
Pace explained that he wanted to understand the natural microbial environments of public places. This kind of knowledge might help discover the microbes (微生物) to be used in a bioterrorist (生物恐怖分子) attack.
1. From the finding of Norman R. Pace, after taking a shower, we might cough or feel tired because ______.| A．it’s easy to get a cold when taking a bath | B．the showerhead carries many bacteria causing illness |
| C．we don’t get cleaned while showering | D．we don’t get a weak immune system |
| A．Hot water could kill most of bacteria in showerheads. |
| B．Of 45 showerheads surveyed in nine cities, 30 carried large amounts of Mycobacterium. |
| C．Changing showerheads is the only way to avoid microorganisms. |
| D．Shower water contains much less bacteria after being left to run for 30 seconds. |
| A．having a shower in the morning is more dangerous than at other time |
| B．the bacteria always threat people’s health |
| C．there is no reason to fear microorganisms for people with strong immune system |
| D．it is better to do some exercise in the morning than have a shower |
| A．cause | B．avoid | C．describe | D．promise |
| A．The train’s movement. | B．Iron particles. |
| C．Train wheels. | D．Air conditioners on the trains. |
8 . When birds’ habitat is destroyed, some species don’t make it while others survive. But what happens at the very beginning of the process, just as a bird’s habitat starts to change? Research in Argentina’s Monte Desert has provided some answers. There are lots of trees, bushes, grasses and flowering plants in the protected parts of the desert. With so many options, most seed-eating birds choose to focus on large grass seeds. The birds can get all the energy and nutrients they need with minimal effort.
But when cattle show up to graze the desert’s natural landscape, birds face changes in food supply. Some birds are happy to change their diets in response. But others, not so much. And it’s the ones set in their ways that are at the highest risk. Understanding how birds react to grazing can help researchers solve the problem of those species.
Ecologists from the Argentine Arid Zones Research Institute compared soil samples from the desert’s Nacunan biosphere reserve to samples from two neighboring cattle farms. It was discovered that grass seeds — the birds’ favorites — were just one-quarter as likely to be found on the farms compared with the reserve. Next, they caught birds to see what they were eating. The Common Diuca-Finch and the Rufous-Collared Sparrow had adjusted their diets, choosing to eat their less preferred options on the farms, even while they still focused on large grass seeds in the reserve.
Meanwhile, the Many-Colored Chaco Finch and the Ringed Warbling-Finch were apparently unable to change their diets. Even on the farms, they worked hard to find the few grass seeds available. If they burn more energy searching for food than they get from the few grass seeds they find, they could starve. At best, their inflexible dietary could limit their ability to reproduce or to care for their young.
Studies like this can help predict which species are at higher risk and help farmers protect these poor species, even while allowing their livestock to graze. For example, the farmers can plant new species for their cattle that will also be more delicious and nutritious for local seed-eating birds. The cows won’t care about the menu change — but the birds sure will.
1. Why can some seed-eating birds easily get their food in the protected parts of the desert?| A．Because of plant diversity. | B．Because there are fewer birds. |
| C．Because there are many small grass seeds. | D．Because of their long-distance flying ability. |
| A．make birds and cattle live in peace | B．help birds change their diets |
| C．make cattle leave the desert | D．help birds most in danger |
| A．Birds only ate large grass seeds on the farms. |
| B．Some birds changed their diets in the reserve. |
| C．There were more birds’ favorite seeds on the farms than in the reserve. |
| D．Some birds chose their favorites in the reserve but other food on the farms. |
| A．drive most birds off the farms | B．change the menu of some birds |
| C．make birds like other seeds best | D．have little effect on birds’ food chains |
| A．Every coin has two sides. | B．Kill two birds with one stone. |
| C．Birds of a feather flock together. | D．There is no garden without weeds. |
9 . While most people don’t think much about garbage, trash (垃圾) is beloved by archaeologist (考古学家). A favorite site for study is a midden (贝丘), an old trash or garbage heap (堆). A midden might contain damaged stone or metal items, which tell us about the weapons and tools people used. Softer materials such as wood, cloth, leather, and baskets are sometimes preserved. They may tell us what people wore, how they carried things, or the kind of toys used by children. Historic household trash heaps often contain broken pottery pieces and even traces of the food they once held.
Most people no longer keep a trash heap by the kitchen door. Instead, garbage is hauled off to landfills (垃圾填埋池). These landfills can still attract archaeologists. The Garbage Project collected information from landfills from 1987 to 1995. Student archaeologists measured tons of garbage from 15 landfills across the United States and Canada. This garbology, the study of garbage, research led to a better understanding of how people have changed what they consume during this period of time. The findings also led to a better awareness of how quickly various items rot. This helped with city planning for garbage disposal and recycling efforts.
Some found objects that may clearly be of archaeological interest, such as arrowheads and spear points. It is typically against the law to collect these on public lands, so they should be left in place. If you take a photo and note the location, you can notify the state archaeologist or the government branch that is in charge of the land, such as the National Park Service or the Bureau of Land Management.
Everyone is responsible for protecting archaeological resources, which is a concept known as “archaeological stewardship.” Sometimes this even means protecting old garbage.
1. Why is old trash important according to archaeologists?| A．It can teach us about the past. |
| B．It might help us locate metal mines. |
| C．It can contribute to modern material industry. |
| D．It might encourage us to protect our environment. |
| A．They conducted a study on modern trash. |
| B．They recycled waste from some landfills. |
| C．They offered some creative city planning ideas. |
| D．They compared ancient trash heaps with modern landfills. |
| A．Donate it to public collections. |
| B．Take it to proper authorities. |
| C．Leave it in a safe place. |
| D．Mark the place of it. |
| A．Past or Future? | B．Trash or Treasure? |
| C．Protection of Damage? | D．Problem or Resource? |
10 . By examining tiny vessels (血管) inside a person’s eyes, doctors might one day be able to predict that person’s risk of early death, according to a new study.
Past research had shown the retina (视网膜), light-sensitive layers of nerve tissue at the back of the eye, as a possible indicator of a person’s bjological age. The retina offers a unique, accessible “window” to evaluate underlying pathological (病理的) processes of some serious diseases that are associated with increased risks of death. In the new study, the researchers turned to a deep-learning technique that could predict a person’s risk of death by analyzing the biological age of the retina.
Their deep-learning model, a type of machine learning and artificial intelligence that’s modeled to learn similar to a human brain, analyzed more than 80.000 images of fundus (眼底) - the internal back surface of the eye that includes the retina. They obtained the images from nearly 47.000 people between the ages of 40 and 69, stored in the UK. Biobank. TO figure out whether their model was accurate, they first analyzed more than 19,000 fundus images taken from more than 1,100 participants who were in relatively good health. The idea was that the retinal biological ages of these people should be fairly similar to their chronological age (实际年龄) .
The model was fairly accurate in predicting retinal ages, with an accuracy of within 3.5 years to chronological ages. They then used the model to assess the remaining nearly 36,000 participants’ fundus photos collected across a span of 11 years. They found that 51 percent of the participants had a “retinal age gap” - the difference between biological and chronological age - of more than 3 years, 28 percent had a gap of more than 5 years and 4.5 percent had a gap of more than 10 years. In other words, these participants had “older” eyes compared to their chronological age.
Those who had larger age gaps had a 49-67 percent higher risk of death from causes other than cardiovascular disease or cancer. With every one year increase in the age gap, the risk of death increased by 2 percent for any cause and 3 percent for causes other than cardiovascular disease and cancer.
1. What can we know about the retina?| A．It causes serious diseases. |
| B．It indicates the risk of death. |
| C．It speeds pathological processes. |
| D．It improves people’s physical health. |
| A．By examining the nerve tissue. |
| B．By studying the human brain, |
| C．By checking the eyesight. |
| D．By analyzing fundus images. |
| A．3.5%. | B．4.5%. | C．28%. | D．51% |
| A．A new study is conducted on tiny vessels |
| B．Image technology is used to predict diseases |
| C．Eyes may reveal a person’s biological age |
| D．A deep-leaning on the retina is necessary |
