Up to one fifth of the Amazon rainforest is emitting more carbon dioxide (CO2), than it absorbs, new research suggests. Results from a decade-long study of greenhouse gases over the Amazon rainforest appear to show around 20% of the total area has become a net source of CO2 in the atmosphere. One of the main causes is deforestation. While trees are growing, they absorb CO2 from the atmosphere; dead trees release it again. However, the fact is that millions of trees have been lost to logging and fires in recent years.
The results of the study, which have not yet been published, have implications for the effort to combat climate change. They suggest that the Amazon rainforest, a vital carbon “store”, or “sink”, that slows the pace of global warming may be turning into a carbon source faster than previously thought. Every two weeks for the past 10 years, a team of scientists led by Professor Luciana Gatti, a researcher at Brazil’s National Institute for Space Research (INPE), has been measuring greenhouse gases by flying aircraft fitted with sensors over different parts of the Amazon basin. What the group found was startling: while most of the rainforest still retains its ability to absorb large quantities of CO2 — especially in wetter years — one portion of the forest, which is especially heavily deforested, appears to have lost that capacity.
Gatti’s research suggests this south-eastern part of the forest, about 20% of the total area, has become a carbon source. “Each year is worse,” she told Newsnight. “We observed that this area in the south-east is an important source of carbon. And it doesn’t matter whether it is a wet year or a dry year. 2017 was a wet year, but it didn’t make any difference.”
A forest can become a source of carbon rather than a “store”, or “sink”, when trees die and emit carbon into the atmosphere. Areas of deforestation also contribute to the Amazon’s inability to absorb carbon.
Carlos Nobre, who co-authored Prof Gatti’s study, called the observation “very worrying” because “it could be showing the beginnings of a major tipping point”. He believes the new findings suggest that in the next 30 years, more than half of the Amazon could transform from rainforest into savanna (稀树草原).
1. Which of the following might Professor Luciana Gatti agree with?| A．Most of the Amazon rainforest absorbs more CO2 in wetter years. |
| B．The Amazon rainforest is on its way to becoming the biggest source of carbon. |
| C．Deforested areas tend to perform better in terms of absorbing carbon in dry years. |
| D．The Amazon rainforest has completely lost its ability to slow the pace of global warming. |
| A．Striking. | B．Convincing. | C．Confusing. | D．Disgusting. |
| A．Northeastern. | B．Southwestern. | C．Southeastern. | D．Northwestern. |
| A．Other worrying phenomena about the Amazon. |
| B．More explanations for the “Amazon tipping point”. |
| C．Other peopled opinions on effects of deforestation. |
| D．Comparison between old findings and new ones. |
相似题推荐
【推荐1】U. S. teens spend more than eight hours a day on screens, and there’s growing concern over it. Now, a new study published by the American Psychological (心理的) Association, confirms that teens seem to feel better about themselves when they cut back.
“Social media can feel like a comparison trap (陷阱),” says study author Helen Thai, a doctoral student in psychology at McGill University. Her research found that limiting screen time to about one hour a day helped anxious teens and young adults feel better about their body image and their appearance. “What I noticed in social media was that I couldn’t help but compare myself.” Thai says. Reading posts from famous people and influencers, as well as people in her own social network, led to a lack of self-confidence.
So, Thai and a team of researchers decided to test whether reducing time on social media would improve body image. They gathered a few hundred volunteers, aged 17-25. all of whom had experienced symptoms (症状) of anxiety or depression — which could make them easily influenced by social media. Half of the volunteers were asked to reduce their social media to 60 minutes a day for three weeks. The other half continued to use social media with no limits.
The researchers gave the volunteers surveys at the beginning and end of the study, including statements such as “I’m pretty happy about the way I look,” and “I am satisfied with my weight.” Among the group that cut social media use, the overall score on appearance improved from 2.95 to 3.15 on a 5-point scale. The change may seem small, but any change in such a short period of time is worth noticing.
“It’s encouraging that college students were willing to cut back screen time, even for three weeks,” psychologist Andrea Graham says. While this study included people with symptoms of anxiety or depression, Graham says it’s worth applying this approach to other groups, such as people with eating problems.
1. What is the probable meaning of the underlined sentence in para 2?| A．Teens are forced to post their own images on social media |
| B．Teens couldn’t help but spend too much time on social media |
| C．Teens tends to compare themselves with others on social media |
| D．Teens are fooled into believing false information on social media |
| A．By listing numbers | B．By giving examples |
| C．By making comparisons | D．By analyzing causes and effects |
| A．The study included people with mental health and eating problems |
| B．There was little difference in appearance score between the two groups |
| C．College students were not willing to reduce screen time for more weeks |
| D．Cutting social media use makes a difference to teens’ opinion of their image |
| A．Less screen time, more self-confidence | B．Social media, a time bomb on your health |
| C．How to improve your image on social media | D．Concern over social media addiction keeps growing |
【推荐2】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.
1. 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．are clear about the relation between weight and mental functions |
| D．do not consider overweight a main cause for low cognitive ability |
| A．losing weight can improve people’s mental functions |
| B．losing weight has little effect on people’s memory |
| C．overweight people are likely to have psychology problems |
| D．overweight people’s abilities of concentration differ greatly |
| A．Slim people are smarter than overweight people. |
| B．Healthy diet is better than exercise in losing weight. |
| C．Overweight people will get smarter by taking more exercise. |
| D．Traditional ways of losing weight are better than operation. |
| A．Body Weight and Health | B．Losing Weight by Operation |
| C．Losing Weight to Sharpen Your Mind | D．Ways to Improve Mental Functions |
【推荐3】Night light from street lamps and phones change the body clock, therefore weakening the body’s ability to control blood sugar levels and raising the risk of diabetes (糖尿病) by more than a quarter, new research has found.
The research was based on almost 100,000 men and women in China who were exposed to artificial light while it was dark outside. Those exposed the most were 28 per cent more likely to develop this condition because of the interference (干预) the light had on the body’s production of melatonin (褪黑激素) which affects our sleep patterns.
Evidence is growing that 24/7 lifestyles are seriously damaging our health by interfering with the production of melatonin. Long-time exposure to residential outdoor artificial light was linked to a rise in blood sugar levels. It was also associated with poorer function of the cells which control blood sugar.
Lead author Dr. Yu Xu, of Ruijin Hospital, Shanghai, said, “Despite over 80 per cent of the world’s population being exposed to light pollution at night, this problem has gained limited attention from scientists until recent years.”
The study estimated more than nine million cases of diabetes in Chinese adults can be attributed to it. A total of 98,658 participants underwent interviews to provide medical, household income, education, way of life, and family history information. Body weight and height were measured to calculate BMI, and blood samples were taken to obtain levels of both fasting and after-meal glucose (葡萄糖).
Participants were assigned an average artificial outdoor light exposure level for the location using satellite images. They were divided into five groups based on highest to lowest exposure. On average, for every 42 people living in regions with the most light pollution, there was one more case of diabetes.
Dr. Xu said, “Exposure to artificial light at night is a common environmental risk factor in modern societies.” More than 99 per cent of people in the US and Europe live under light-polluted skies. Earth’s 24-hour day-night cycle has resulted in most organisms, including humans, having an inbuilt circadian (昼夜的) timing system, but light pollution has been found to change the circadian rhythm of insects, birds and other animals, resulting in early death and loss of biodiversity.
1. How can artificial light affect people’s health?| A．It can harm people’s eyesight. |
| B．It can affect people’s sleep patterns. |
| C．It can weaken the function of brain cells. |
| D．It can increase the production of melatonin. |
| A．Work. | B．Sleep. | C．Lifestyle. | D．Marriage. |
| A．Previous findings. | B．High technology. |
| C．International assistance. | D．Artificial chemicals. |
| A．Artificial light is harming the world. |
| B．People are fighting against pollution. |
| C．The waste of electricity is the primary issue. |
| D．Most light pollution is from the US and Europe. |
【推荐1】Although the idea of “zero emission, net carbon-positive, sustainable (可持续)” development was promoted worldwide, most cities are at a loss what to do or even some have objected to it. But in Liuzhou, a city in southern China, attitudes could not be more different.
The Liuzhou Municipality Urban Planning Bureau has signed up Italian architect Stefano Boeri, the father of the forest city movement, to build a self-contained community for up to 30,000 people. He is the go-to man for such projects thanks to the success of his “vertical forests”, two residential (住宅的) towers. Completed in 2014, they remove up to 17.5 tons of soot (煤烟) from the air each year, and a year later one of them was named Best Tall Building Worldwide.
The Liuzhou project is a much more ambitious undertaking, however. Its homes, hospitals, hotels, schools and offices will be built on a 340-acre site in what Boeri calls the first attempt to create an “urban environment that is really trying to find a balance with nature”. Its 100 species of plant life are expected to absorb almost 10,000 tons of carbon dioxide and 57 tons of pollutants per year, while at the same time producing 900 tons of life-giving oxygen.
Although the architects haven’t published the cost of the forest city, the Milan towers cost only five percent more than traditional skyscrapers.
The construction of his forest city at Liuzhou is set to begin in 2020, and there is still a great deal of planning and research required before a projected completion date can be set. However, Boeri remains optimistic about the project and has confidence in the soundness of his vision: “I really think that bringing forests into the city is a way to deal with global warming.”
1. What’s Liuzhou’s attitude towards the sustainable development?| A．Approving. | B．Cautious. | C．Unfavorable. | D．Doubtful. |
| A．He volunteered to do the project. |
| B．He is a famous architect in the world. |
| C．He is the father of the forest recovery. |
| D．He has gained experience in similar projects. |
| A．The architects. | B．The two towers. |
| C．Forests in the city. | D．The residents of the city. |
| A．To provide more jobs. | B．To bring forest into city. |
| C．To solve house shortage. | D．To improve the environment. |
【推荐2】Throughout history, many species of animals have been threatened with dying out. When Europeans first arrived in North America, more than 60 million buffalo (水牛) lived on the continent. Yet hunting the buffalo was so popular during the 19th century that by 1900 the animal’s population had fallen to about 400 before the government stepped in to protect the species. In some countries today, the elephant faces a similar challenge, as illegal hunters kill the animals for the ivory (象牙) in their tusks.
Yet not all animals with commercial value face this threat (威胁). The cow, for example, is a valuable source of food, but no one worries that the cow will soon die out. Why does the commercial value of ivory threaten the elephant, while the commercial value of beef protects the cow?
The reason is that elephants are a common resource, while cows are private goods which only belong to their owners. Elephants wander freely without any owners. The hunter has a strong motivation to kill as many elephants as he can find. Because the number of illegal hunters is big, each has only a little desire to protect the elephant population. By contrast, cattle live on farms that are privately owned. Each farmer makes great effort to keep the cattle population on his farm because he gets the benefit of these efforts.
Governments have tried to solve the elephant’s problem in two ways. Some countries, such as Kenya and Uganda, have made it illegal to kill elephants and sell their ivory. Yet these laws have been hard to put into effect, and elephant numbers have continued to reduce. By contrast, other countries, such as Malawi and Namibia, have made elephants private goods and allowed people to kill elephants, but only those who own these elephants.
With private ownership and the profit (利润) now on its side, the African elephant might someday be as safe from dying out as the cow. The ancient Greek philosopher Aristotle pointed out the problem with common resources: “What is common to many is taken least care of, for all men attach greater importance to what is their own than for what they have together with others.”
1. Why does the author mention buffalo in paragraph 1?| A．To introduce a similar threat to elephants. |
| B．To provide an example of species dying out. |
| C．To offer an explanation for government policies. |
| D．To present the statistics of the buffalo in America. |
| A．They are under different law protection. |
| B．They attract different groups of hunters. |
| C．They contain different commercial value. |
| D．They belong to different ownership types. |
| A．Bans on killing elephants for ivory. |
| B．Effective laws for elephant protection. |
| C．Methods of making elephants private goods. |
| D．Government policies on the elephant’s problem. |
| A．Because elephants don’t fight back. |
| B．Because elephants don’t have exact owners. |
| C．Because local government haven’t protected them. |
| D．Because elephants are more valuable than other animals. |
| A．People pay little attention to others’ resources. |
| B．People want to profit from common resources. |
| C．People care more about their own resources. |
| D．People tend to take what they own for granted. |
【推荐3】For long, Preifer Fall Trail (路线) was a most popular attraction in Big Sur. Annually, thousands of people hiked the trail. Unfortunately, the trail, along with stairs, signs, railings, an observation station and wooden bridges, was destroyed in the 2008 Basin Complex Fire. But now a new trail has risen from the burned land.
With its amazing rocky coastline and mountains, Big Sur, the writer Henry Miller once said, is “the face of the earth as the creator intended it to look.” But the landscape always suffers natural disasters. There have been three major wildfires in Big Sur in the past years. “You can still see the impacts there,” said John Hiles, a state parks repair team leader, pointing to black marks 30 feet up a huge redwood.
Parks planners designed a new track, moving the trail out of the river to reduce its impact on the environment. People from the California protection group, state parks department and the nonprofit organization put in 66,000 hours of work over the past four years. They built 160 redwood stairs and dragged hundreds of 16-foot-long redwood sticks by hand to build railings. They removed 4,150 square feet of old building stuff, enough to cover a basketball court. They used iron cables and pulleys (缆线和滑轮) to build a 70-foot long wooden bridge over the hills. “Nature is probably the best place to learn,” Hiles said. “More than any college or school, you learn so many life lessons out here.”
However, the huge Soberanes Fire s wept through the area in 2016, putting a stop to the work. When they began again in 2017, great river storms flooded the area and damaged part of Highway 1. Everybody gathered around this project. They saw the loss. They missed it. They wanted it to come back. They kept combining efforts. It’s been a long journey, but worth the wait.
1. What can we learn about Preifer Fall Trail?| A．It is an attraction rebuilt in 2008. | B．It met with many natural disasters. |
| C．It features man-made landscape. | D．It is an addition to a previous track. |
| A．By moving the trail off watercourse. | B．By using huge redwood sticks. |
| C．By recycling the old building stuff. | D．By applying iron cables and pulleys. |
| A．Limiting and typical. | B．Adventurous but smooth. |
| C．Mysterious and attractive. | D．Tough but rewarding. |
| A．The rise and fall of a hiking trail. | B．California protection projects. |
| C．The recovery of a lost attraction. | D．Journeys into wilderness. |
When I was fifteen, I was shy. I remember an attractive girl trying to talk with me. My shyness made me focus on me instead of her. I heard my own voice but not hers and I thought about what I was trying to say instead of what she was trying to say.
To overcome shyness you need to learn to relax. This gives you the space to practice certain conversational skills. Relaxed socializing (社交) is so pleasurable. To start reducing your own shyness, I want you to absorb the following tips and ideas and start to put them into practice.
Focus your attention away from yourself. Notice what other people are wearing and make a mental note, listen to their conversation, imagine where they might live, and make a point of remembering names. Not only does this give you more to talk about, it also reduces social anxiety, leaving you feeling calmer.
Ask people open questions. Many people like to talk about themselves and will find you interesting if you find them interesting. Ask questions that require more than a “yes” or “no” response such as “What do you like about this place?’ rather than “Do you like this place?” Once they have answered, you can use add-on (追加) questions connected with the first such as “What other places do you like in this city?” Next you can express your views. This is a great way to get the conversation going.
Now I love meeting new people and suspect that my current social confidence would be unrecognizable to my fifteen-year-old self.
1. The author didn’t pay attention to what the girl was saying because .
| A．her voice was very low |
| B．he was shy and nervous |
| C．he was attracted by her appearance |
| D．he wasn’t interested in her topic |
| A．pay much attention to yourself |
| B．find a beautiful girl to talk with |
| C．learn to talk to others in a relaxed way |
| D．ask people some interesting questions |
| A．people will notice our appearance if we focus on their looks |
| B．shy people will have no friends unless they change themselves |
| C．shy people may suffer a great deal and may be less happy |
| D．girls like to show off their voices in front of boys |
| A．What a lovely day, isn’t it? |
| B．Do you like playing basketball? |
| C．Do you think he will pass the exam? |
| D．Why do you find that English is hard to learn? |
【推荐2】My four-and eight-year-olds are closer now than they were before the pandemic. I can hear the sounds of giggling from their bedroom several times a night. But the more time my girls spend together, the more they fight, too. The most common battlegrounds for my kids are injustices and fighting for position.
On days when we are trapped in the house together and their screaming matches reach operatic levels, their dad and I worry we did something horribly wrong as parents to encourage this volume of conflict. But according to Jeanine Vivona, a professor of psychology at the College of New Jersey who studies sibling rivalry (较量), “competition with siblings is just a fact of life. And we can just try to manage it as best we can.”
Studies have shown that sibling conflicts may occur up to eight times an hour. “Conflict does decrease into adolescence; it’s sort of levels off,” said Mark Ethan Feinberg, a research professor at Pennsylvania State University. “Early and middle childhood are particularly difficult times for sibling aggression.”
While most siblings aren’t fighting for actual quarrels, psychologically, sibling rivalry serves a developmental purpose: it helps children figure out what is unique and special about themselves, known as “differentiation”. Children want to be seen as the most special by their parents, so they’re always going to push for preferential treatment over their siblings. But they may also shape their interests and personalities around their siblings’ skills and desires.
For example, let’s say the older son is a soccer star. The younger child or children may then avoid soccer altogether, either because they are afraid they won’t be as good or because they fear they might be better—and they don’t want to take that risk either.
1. Why is there conflict between the author’s daughters?| A．Because they play the screaming matches. |
| B．Because they always compete for priority. |
| C．Because they can’t stand living with each other. |
| D．Because they receive obviously unfair treatment. |
| A．Sibling rivalry could be useful as motivation for children. |
| B．Parents should intervene sibling rivalry as much as they can. |
| C．Most sibling conflicts begin to fall when children become adults. |
| D．Life throughout childhood will be miserable due to sibling rivalry. |
| A．Kids’ struggle with sibling rivalry |
| B．Parenting solutions to sibling rivalry |
| C．The psychology behind sibling rivalry |
| D．An unintended upside of sibling rivalry |
【推荐3】In the Amazon rainforest of Venezuela，Yanomami hunter-gatherers exist on cassava, palm hearts and wild banana. They also hunt frogs and monkeys using techniques that would have been familiar to their ancestors 11,000 years ago. The extraordinary continuity of their culture, and the fact that some of the groups have had little contact with outsiders,led biologists to wonder whether the Yanomami might reveal what the human digestive system looked like before industrialization supplied the world with processed foods and antibiotics.
In 2009, researchers had a chance to find out in a previously unknown Yanomami village. Health workers collected fecal (排泄物的) and skin samples from about 30 villagers. When researchers cultured and analyzed microbes in the feces, the scientists discovered whole categories of bacteria that were absent from the guts (肠道) of people from industrialized countries. Even more striking, they found the microbial population in the average Westerner to be about half as diverse as the community inside these hunter-gatherers. The researchers realized that the microbes might have implications beyond basic science. People's microbial communities are believed to play a role in disorders like obesity, diabetes and Alzheimer's, which shorten lives and overburden health care systems. These disorders don't trouble these preindustrial Amerindians, however. So researchers want to learn which microbes protect them and figure out how to reintroduce them in modern societies. It has the potential to affect health more profoundly than the diseevery of the fabled Fountain of Youth.
But the opportunity might be more fleeting than youth itself. “The world is becoming urban so fast.” says microbiologist Maria Gloria, co-author of a 2015 study that reveals the Yanomami microbiome. “Our lifestyles are killing microbial diversity.” And although nobody has yet determined exactly what the Yanomami mystery bugs are doing, and how they improve an individual's health，she believes that scientists need to collect and preserve as many microbes as possible in anticipation of future breakthroughs. “We cannot afford to wait,” she says, “or we'll have lost the high diversity of the human microbiome of traditional peoples before we understand how to use the microbiome to improve health. ”
1. What did the researchers find out about the villagers in 2009?| A．The hunter-gathers had a different digestive system. |
| B．Microbial diversity was responsible for many disorders. |
| C．People from industrialized countries had less diverse microbes. |
| D．Some categories of bacteria did not exist in those villagers' guts. |
| A．The opportunity is even more precious than youth itself. |
| B．The opportunity is of greater significance to modern science. |
| C．Compared with youth，such an opportunity seems more appealing. |
| D．The opportunity disappears so quickly that we can't afford to lose it. |
| A．Concerned. | B．Optimistic. |
| C．Sceptical. | D．Critical. |
| A．Processed foods and antibiotics have changed human digestive system. |
| B．More efforts are needed to solve the mystery of Yanomami microbiome. |
| C．Treating diseases by introducing beneficial bacteria has been made possible. |
| D．The discovery of those microbes will help cure many life-threatening diseases. |
