Imagine living on the edge of a vast desert, which is moving quietly closer to your village every day and covering your fields. The desert is on the move. This is called desertification.
Desertification occurs in regions close to an already existing desert. It generally arises from two related causes. The first is over-use of water in the area. There is not enough water in any case, and if it is not carefully used, disaster can follow. As time goes on, water shortages make farming more and more difficult. In some places, locals can remember local lakes and marshes which were once the homes for all kinds of fish and birds. They have been completely buried by the sand now. Farmers leave the land, and fields are replaced by deserts.
The second cause is misuse or over-use of the land. This means that the wrong crops are planted and need more water than is available. Ploughing large fields and removing bushes and trees means that the wind will blow away the soil. Once the soil is lost, it is hard to replace, and if there is rain, it has nowhere to go, and brings no benefit.
It is not only the farmers and villagers who suffer. Every spring, the skies over some of eastern cities, thousands of kilometers away from the deserts, can be darkened by sandstorms. Dust from deserts can have a great effect on weather systems. While desertification is perhaps being partly caused by global warming, these sandstorms can make global warming worse by adding to what is known as the greenhouse effect.
What can be done to slow down or stop the process of desertification? A great deal of work is already under way. Obviously first steps are to find new water sources. Tree planting can help, by providing barriers between desert and rich field. Some types of grass also hold the soil together, and stop the wind taking it. Without these efforts, it will be harder and harder to stop the world’s deserts in their tracks, and more and more farmers will give up and head for cities. The lesson to be learnt lies beneath the sand.
___________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________
2 . Hailing from Sweden, “plogging” is a fitness craze that sees participants pick up plastic litter while jogging adding a virtuous, environmentally driven element to the sport. Plogging appears to have started around 2016, but is now going global, due to increasing awareness and
The appeal of plogging is its
Running and good causes have always gone
Anything that’s getting people out in nature and connecting
We need to keep momentum high and the pressure up, and empower people through
The plastic Patrol app allows users to
Plogging isn’t the first fitness trend to combine running with a good cause, Here are some of our favourites:
Good Gym
Its idea is simple: go for a run, visit an elderly person, have a chat and some tea, and run back.
Guide Running
Guide runners volunteer their time to helping blind people get
Start-up Stuart Delivery and the Church Housing Trust collaborated last year in bringing clothing and healthy food to the homeless. Deliveries are mostly made by bike, so those who deliver keep fit while helping rough sleepers(无家可归者).
1.| A．satisfaction | B．hesitation | C．fear | D．control |
| A．complexity | B．simplicity | C．instrument | D．expense |
| A．substance | B．responsibility | C．value | D．weight |
| A．one on one | B．head to toe | C．hand in hand | D．on and off |
| A．positively | B．neutrally | C．objectively | D．fairly |
| A．accuse | B．rid | C．assure | D．rob |
| A．shift | B．interest | C．aid | D．delight |
| A．motives | B．performances | C．exercises | D．initiatives |
| A．eliminate | B．map | C．seek | D．degrade |
| A．leading | B．devoting | C．ending | D．uploading |
| A．Disappointment | B．Tiredness | C．Sickness | D．Loneliness |
| A．therefore | B．moreover | C．however | D．instead |
| A．excited | B．ready | C．active | D．smart |
| A．visually | B．audibly | C．visibly | D．sensibly |
| A．Running | B．Plogging | C．Driving | D．Cycling |
Would a person born blind, who has learned to distinguish objects by touch, be able to recognize them purely by sight if he regained the ability to see? The question, known as Molyneux’s problem, is about whether the human mind has a built-in concept of shapes that is so innate(天生的) that such a blind person could immediately recognize an object with restored vision. The alternative is that the concepts of shapes are not innate but have to be learned by exploring an object through sight, touch and other senses.
After their attempt to test it in blind children failed, Lars Chittka of Queen Mary University of London and his colleagues have taken another attempt at finding an answer, this time using another species. To test whether bumblebees can form an internal representation of objects, they first trained the insects to distinguish globes from cubes using a sugar reward. The bees were trained in the light, where they could see but not touch the objects. Then they were tested in the dark, where they could touch but not see the globes or cubes. The researchers found that the bumblebees spent more time in contact with the shape they had been trained to associate with the sugar reward, even though they had to rely on touch rather than sight to distinguish the objects.
The researchers also did the reverse test with untrained bumblebees, first teaching them with rewards in the dark and then testing them in the light. Again, the bees were able to recognize the shape associated with the sugar reward, though they had to rely on sight rather than touch in the test. In short, bees have solved Molyneux's problem because the fact suggests that they can picture object features and access them through sight or touch.
However, some experts express their warnings. Jonathan Birch, a philosopher of science, cautions that the bees may have had prior experience associating visual and tactile(触觉的) information about straight edges and curved surfaces in the context of their nests, so it is not possible to eliminate the possibility that some of the cross-sensory concept is learned rather than innate.
4 . It’s almost spring, the time of year when the change in seasons could lead to some pretty fascinating cloud activity in the sky. NASA and the GLOBE Program are inviting you to take part in a citizen science cloud observation challenge. The GLOBE Program is an international science and education program that provides students and the public with the opportunity to participate in data collection and the scientific process.
From March 15 through April 15, citizen scientists of all ages can make up to 10 cloud observations per day using the GLOBE Observer app or one of the other data entry options (for trained GLOBE members). Challenge participants with the most observations will be congratulated by a NASA scientist in a video posted on the GLOBE Program’s website and on social media.
“The GLOBE Program is offering this challenge to show people how important it is to NASA to have citizen scientist observations: observations from the ground up,” said Marile Colon Robles, lead for the GLOBE Clouds team at NASA’s Langley Research Center in Hampton, Virginia. “We’re going from winter to spring, so the types of storms will change, which will also change the types of clouds.
Researchers use, and value, this citizen science cloud data because it helps to validate data from Earth-observing instruments. Scientists at Langley work with a set of six instruments known as the Clouds and the Earth’s Radiant Energy System(CERES)
Even though CERES’ instruments use advanced technology, it is not always easy for researchers to positively identify all types of clouds in their images. For example, it can be difficult to differ thin, wispy cirrus clouds(细小的卷云)from snow since both are cold and bright; even more so when cirrus clouds are above a surface with patchy snow(片状雪)or snow cover. One solution to this problem is to look at satellite images from a particular area and compare them to data submitted by citizen scientists on the ground.
“Looking at what an observer recorded as clouds and looking at their surface observations really helps us better understand the images that were matched from the satellite,” said Colon Robles.
You don’t have to be a cloud-gazing professional to participate. For those who want to be part of the challenge but don’t have a lot of experience identifying clouds, Colon Robles offers the following advice: “Just go outside.” The more clouds you observe, she said, the more comfortable you’ll be collecting data.
1. Why do researchers launch the cloud observation challenge?| A．The GLOBE Program is badly short of hands. |
| B．The technology CERES uses is not that advanced |
| C．Scientists can compare data from different instruments. |
| D．Cirrus clouds are difficult to identify when with snow cover |
| A．create | B．cancel |
| C．count | D．confirm |
| A．Citizen observers can only submit their data by means of an app |
| B．Observers submitting the most observations can get a special prize |
| C．Observations from the ground are not as valuable as satellite images |
| D．The data collected by citizen scientists will be posted on social media |
| A．NASA Employs New members |
| B．Cloud Activities Bring a New Challenge |
| C．Citizens Gain Experience through Observation |
| D．Professionals Teach You to Observe Clouds |
Fan Lihong, her parents and her daughter are standing along Madang Road in Shanghai, cups in hand. Many
“I have been using my own cups to buy coffee this year. Using my own cup is
Manner Coffee, which operates over 100 stores across China, sells nearly 100,000 cups of coffee per day. Around half of their customers bring their own cups, according to Ning Yihan, marketing representative of Manner. We started to encourage consumers to bring their own non-disposable cups to Manner stores since the day we
Other countries around the world have also set their eyes on reducing the use of disposable paper cups and encourage people
6 . Is Climate Change Consuming Your Favorite Foods?
As the increased amount of carbon dioxide in the atmosphere, heat stress, longer droughts(干旱), and more intense rainfalls linked to global warming continue to upset our daily weather, we often forget they also impact the quantity, quality, and growing
To start with what is
And coffee's culinary (烹饪的) cousin, cacao (aka chocolate),is also suffering stress from global warming's rising temperatures. But for chocolate, it isn't the warmer climate alone that's the problem. Cacao trees actually
Another notably nutritious plant, peanut grows best when it gets five months of continuous warm weather and 20 to 40 inches of rain. Anything
Finally, in the world of sea, as air temperatures rise, oceans and waterways absorb some of the heat and undergo warming of their own. The result is the
| A．attitudes | B．choices | C．locations | D．resources |
| A．contributed | B．earned | C．featured | D．reflected |
| A．amazing | B．unique | C．typical | D．scarce |
| A．necessary | B．luxurious | C．practical | D．original |
| A．defend | B．rob | C．shock | D．infect |
| A．increases | B．cuts | C．changes | D．failure |
| A．survive | B．prefer | C．admire | D．encounter |
| A．Moreover | B．By contrast | C．However | D．Therefore |
| A．accompanied | B．influenced | C．blocked | D．doubled |
| A．unlikely | B．irrelevant | C．inappropriate | D．immeasurable |
| A．more | B．less | C．warmer | D．colder |
| A．patterns | B．depths | C．extremes | D．ends |
| A．rainy | B．shiny | C．freezing | D．dry |
| A．revolution | B．shrink | C．extinction | D．evolution |
| A．silenced | B．heightened | C．changed | D．minimized |
7 . As the railroads and the highways shaped the American West in the past centuries, a new electrical generating (发电) and transmission (输送) system for the 21th century will leave a lasting mark on the West, for better or worse. Much of the real significance of railroads and highways is not in their direct physical effect on the scenery, but in the ways that they affect the suurouding community. The same is true of big solar plants and the power lines that will be laid dowm to move electricity around.
The 19th century saw land grants (政府拨地) offered to railroad companies to build the transcontinental railroads, leaving public land in between privately owned land. In much of the West, some of the railroad sections were developed while others remained undeveloped, and in both cases the landownership has presented unique challenges to land management. With the completion of the interstate highway system, many of the small towns, which sprang up as railway stops and developed well, have lost their lifeblood and died.
Big solar plants and their power lines will also have effects far beyond their direct footprint in the west. This is not an argument against building them. We need alternative energy badly, and to really take advantage of it we need to be able to move electricity around far more readily than we can now.
So trade-offs will have to be made. Some scenic sport will be sacrificed. Some species (物种) will be forced to move, or will be carefully moved to special accommodations. Deals will be struck to reduce the immediate effects.
The lasting effects of these trade-offs are another matter. The 21st century development of the American west as an ideal place for alternative energy is going to throw off a lot of power and money in the region. There are chances for that power and money to do a lot of good. But it is just as likely that they will be spent wastefully and will leave new problems behind, just like the railroad and the highway.
The money set aside in negotiated trade — offs and the institution that control it will shape the West far beyond the immediate footprint of power plants and transmission lines. So let’s remember the effects of the railroads and the highways as we construct these new power plants in the West.
1. What was the problem caused by the construction of the railways?| A．Small towns along the railways became abandoned. |
| B．Some railroad stops remained. |
| C．Land in the West was hard to manage. |
| D．Land grants went into private hands. |
| A．The transmission of power | B．The use of money and power |
| C．The conservation of solar energy | D．The selection of an ideal place |
| A．Cautious | B．Approving | C．Doubtful | D．Disapproving |
| A．How the Railways Have Affected the West |
| B．How Solar Energy Could Reshape the West |
| C．How the Effects of Power Plants Can Be Reduced |
| D．How the Problems of the Highways Have Been Settled |
8 . A tiny clue found in ancient deposits has unlocked big secrets about Greenland’s past and future climate. Just beyond the northwest edge of the vast Greenland Ice Sheet, researchers have discovered lake mud that have survived the last ice age. The mud, and remains of common flies in it, record two interglacial periods（间冰期）in northwest Greenland.
Although researchers have long known these two periods—the early Holocene and Last Interglacial—experienced warming in the Arctic, the mix of fly species shows that Greenland was even warmer than previously thought. “As far as we know, it has never been found in Greenland. We think this is the first time anyone has reported it in ancient deposits or modern lakes there,” Axford said. “We were really surprised to see how far north it migrated (迁徙).”
This new information could help researchers better measure Greenland’s sensitivity to warming, by testing and improving models of climate and ice sheet behaviour. Those models could then improve predictions of how Greenland’s ice sheet might respond to man-made global warming. After all, Greenland covers 80 per cent of the Arctic country and holds enough ice to equal 20 feet of global sea level. “Northwest Greenland might feel really remote, but what happens to that ice sheet is going to matter to everyone in every coastal city around the world,” said Yarrow Axford, an associate professor in the team. “One of the big uncertainties in climate science is how fast the Earth changes when it gets warmer. Geology gives us an opportunity to see what happened when the Earth was warmer than today,” said Axford.
People might be surprised to see how today’s Greenland looked during the last two interglacial periods. During the Last Interglacial, global sea levels increased by 15 to 30 feet, largely due to thinning of Greenland and Antarctica’s ice sheets. However, now researchers believe northern Greenland’s ice sheet experienced stronger warming than previously thought, which could mean that Greenland is more responsible for that sea-level rise.
Finding lake deposits older than about 10,000 years, however, has been historically very difficult in Greenland. To measure these ancient temperatures, researchers look to ice cores (冰核) and lake deposits. Since ice and lake deposits form by a gradual buildup on annual layers of snow or mud, these cores contain history of the past. By looking through the layers, researchers can obtain climate clues from centuries ago.
1. Why are the remains of flies mentioned in the first two paragraphs?| A．They serve as evidence that there is still life in the Northwest Greenland. |
| B．They were one of the many ancient lives that were left in the Greenland mud. |
| C．They are indicators that Greenland was much warmer than previously thought. |
| D．They help the researchers realize that there was once a warm period in the Arctic. |
| A．researchers have no idea how to measure Greenland’s warming speed |
| B．it can help researchers better predict Greenland’s response to warming |
| C．people should be more sensitive to the changes in the ice in Greenland |
| D．it is uncertain how fast the Earth changes with man-made global warming |
| A．It is easier for today’s scientists to find ancient lake deposits. |
| B．People are surprised at the landscape feature of Greenland today. |
| C．Researchers measure the changing temperatures by directly examining mud. |
| D．Greenland holds enough ice that might one day threaten life in coastal cities. |
| A．Greenland Used to Be Much Greener |
| B．Earth Once Experienced Warm Periods |
| C．Coastal Cities Warned of Coming Disasters |
| D．Northwest Greenland, A Perfect Destination |
9 . When prehistoric man arrived in new parts of the world, something strange happened to the large animals. They suddenly became extinct. Smaller species survived. The large, slow-growing animals were easy game, and were quickly hunted to extinction. Now something similar could be happening in the oceans.
That the seas are being overfished has been known for years. What researchers such as Ransom Myers and Boris Worm have shown is just how fast things are changing. They have looked at half a century of data from fisheries around the world. Their methods do not attempt to estimate the actual biomass (the amount of living biological matter) of fish species in particular parts of the ocean, but rather changes in that biomass over time. According to their latest paper published in Nature, the biomass of large predators (animals that kill and eat other animals) in a new fishery is reduced on average by 80% within 15 years of the start of exploitation. In some long-fished areas, it has halved again since then.
Dr. Worm acknowledges that the figures are conservative. One reason for this is that fishing technology has improved. Today's vessels (船)can find their prey using satellites and sonar, which were not available 50 years ago. That means a higher proportion of what is in the sea is being caught, so the real difference between present and past is likely to be worse than the one recorded by changes in catch sizes. In the early days, too, longlines (多钩长线) would have been more filled with fish. Some individuals would therefore not have been caught, since no baited hooks (带饵钩)would have been available to trap them, leading to an underestimate of fish stocks in the past. Furthermore, in the early days of longline fishing, a lot of fish were lost to sharks after they had been hooked. That is no longer a problem, because there are fewer sharks around now。
Dr. Myers and Dr. Worm argue that their work gives a correct baseline, which future management efforts must take into account. They believe the data support an idea current among marine biologists, that of the “shifting baseline". The idea is that people have failed to detect the massive changes which have happened in the ocean because they have been looking back only a relatively short time into the past. That matters because theory suggests that the maximum sustainable yield （产量）that can be cropped from a fishery comes when the biomass of a target species is about 50% of its original levels。. Most fisheries are well below that, which is a bad way to do business.
1. The extinction of large prehistoric animals is noted to suggest that____.| A．large animals were easily hurt in the changing environment |
| B．small species survived as large animals disappeared |
| C．large sea animals may face the same threat today |
| D．slow-growing fish outlive fast-growing ones |
| A．fishing technology has improved rapidly |
| B．the catch-sizes are actually smaller than recorded |
| C．the marine biomass has suffered a greater loss |
| D．the data collected so far are out of date |
| A．people should look for a baseline that can't work for a longer time |
| B．fisheries should keep the yield below 50% of the biomass |
| C．the ocean biomass should restore its original level |
| D．people should adjust the fishing baseline to changing situation |
| A．biomass level | B．management efficiency |
| C．catch-size limits | D．technological application |
10 . How Saving Wildlife Benefits Humans
It’s no secret that we’ve lost an overwhelming number of species within that last four decades. These species have all but
One of the first great rules of terrestrial (陆地的) biology is “no species is forever.”
The Earth consists of plants, animals, water, land, the atmosphere, and humans. Biodiversity (生物多样性)
One convincing benefit that comes from wildlife conservation efforts is that it ensures food
Another benefit that comes from wildlife conservation is that these
Perhaps the most convincing benefit that comes from wildlife conservation is that it provides us with
Our unsustainable, unconscious, self-interested relationship with the environment has led us into an extremely destructible world. If we do not take action and
| A．changed | B．existed | C．disappeared | D．evolved |
| A．Furthermore | B．However | C．Therefore | D．Otherwise |
| A．extinction | B．destruction | C．evolution | D．immigration |
| A．threatens | B．localizes | C．strengthens | D．endangers |
| A．infrequently | B．potentially | C．regionally | D．directly |
| A．management | B．inspection | C．development | D．security |
| A．identified | B．cultivated | C．exploited | D．valued |
| A．initiatives | B．consequences | C．intentions | D．contributions |
| A．In addition | B．After all | C．In particular | D．By contrast |
| A．adapted | B．turned | C．adjusted | D．linked |
| A．protections | B．opportunities | C．services | D．nutrients |
| A．standard | B．welcome | C．scarce | D．profitable |
| A．discourage | B．attract | C．forbid | D．protect |
| A．feel like | B．keep on | C．set about | D．argue for |
| A．irreplaceable | B．unpredictable | C．unlimited | D．imbalanced |
