1 . Polar bears are icons of the Arctic. Detailed monitoring of their populations is crucial for their conservation—but because polar bears are so difficult to find, we are missing critical data about population size. Scientists have now developed a new tool to help: DNA analysis using skin cells left in the bears’ footprints in the snow.
The scientists were inspired by the techniques that can be applied to tiny, degraded DNA samples. With these techniques, it isn’t necessary to physically capture bears, which can be stressful and dangerous for both bears and humans. Instead, the researchers can turn to the snow tracks of polar bears and look at sources of DNA left in passing—environmental DNA. "The tracks usually contain fresh cells, and the DNA is intact because of the cold’ storage’ temperature, "said Dr. Melanie Lancaster of the World Wide Fund, lead author.
The scientists collected snow from individual tracks made by Alaskan polar bears in the wild. Additional materials like hair and saliva(唾液)were sampled, confirming that the tracks provided accurate genotype(基因型) 24 wild polar bear tracks were sampled. The researchers melted and filtered the snow to collect environmental DNA, then carried out micro-satellite analysis. Although the concentrations (浓度)of DNA taken from trucks sampled in the wild were very low, 13 of the wild polar bear samples could be genotype, identifying 12 different individuals.
This technique has huge potential to inform conservation of these animals, to better understand their populations and behavior. Although the sampling has a lower success rate, ease of collection means that it can significantly expand sample sizes.
"We hope this method will be taken up by the polar bear research community, with the involvement of hunters, volunteers, and local communities, as a new way to collect information on polar bears, "said Lancaster. "We also hope the method will be expanded to other animals living in snowy environments. "
1. Why do scientists develop the new method?| A．To improve the environment in the Aretic. |
| B．To protect humans from the polar bears attack. |
| C．To find solutions to global climate change. |
| D．To gather essential data for monitoring polar bears. |
| A．Unknown. |
| B．Undamaged. |
| C．Unusual. |
| D．Unstable. |
| A．They tracked and caught polar bears in the wild. |
| B．They recorded the bears’ behaviors with cameras. |
| C．They analyzed DNA from polar bears’ snowy footprints. |
| D．They compared the polar bears’ genotype with other animals? |
| A．Disapproving. |
| B．Favorable. |
| C．Uncertain. |
| D．Suspicious. |
2 . Tourist Guide to the National Gallery
Opening hours: Daily 10: 00 am- -6: 00 pm; Friday 10: 00 am- 9: 00 pm
Closed: 2426 December
Reasons to visit:
With over 2, 300 paintings in the collection, there are hundreds of reasons to visit the Gallery. Here are some to get you started...
Get into great art. From Leonardo da Vinci to Vincent van Gogh: See priceless works of art for free.
Get creative. Brush up your skills, and create your own great works of art...
Learn about art. Discover more about paintings...
Regulations:
Talk in a low voice when you use your cellphone in the gallery
Please do not touch the paintings or other exhibits. Do not take pets in or cross the barriers.
Consume food and drink in designated areas only i.e. not in rooms that contain paintings.
Follow our no smoking policy in any part of the building.
Follow our no photograph policy in exhibitions where a sign is displayed.
Access:
The National Gallery aims to make access to the paintings enjoyable and welcoming to the widest possible public. There are a range of facilities to help you see the collection, visit exhibitions and come to events.
The Gallery offers British Sign Language-interpreted talks on paintings for visitors who are deaf, and special art sessions(展期) for visitors who can't see.
Address: The National Gallery, Trafalgar Square London WC2N 5DN
Click here to find more information.
1. What are visitors allowed to do in the National Gallery?| A．Make a phone call. | B．Take a dog in. |
| C．Smoke a cigarette. | D．Take photos. |
| A．Young visitors. | B．Deaf visitors. |
| C．Blind visitors. | D．Old visitors. |
| A．In a newspaper. | B．On a poster. |
| C．In a magazine. | D．On the Internet. |
3 . "While protected areas are generally designed to be safe havens, unchecked human pressures car have a negative impact," says zoologist Femke Broekhuis, lead author of a new study by the University of Oxford that has raised questions about levels of tourism in protected areas.
The study focused on female cheetahs（非洲猎豹）in the Maasai Mara National Reserve, Kenya. Cheetahs have babies of one to six, few of which make it to adulthood. The study claims that the already low cubs（幼崽）survival rate is made even worse by tourist pressure. It found that one or no cub survived to adulthood in areas with high levels of tourism, while an average of two survived in areas with low levels.
The higher death rate is likely to be caused by poor food supplies for the cubs. "Cheetahs, especially those with cubs, are a major tourist attraction and commonly attract large numbers of vehicles," says Broekhuis. "High tourist numbers have been found to negatively impact cheetah hunts and even if a hunt is successful, the presence of tourists can result in a cheetah abandoning its kill."
While Broekhuis is eager to stress the positive role of conservation, she also admits the results are worrying. Cheetah numbers are already being squeezed. Predation（掠夺）from lions as well as habitat reduction means the big cats have experienced sharp population decline. In fact, their numbers are thought to have halved in Kenya in the past 40 years to around 7,000. They have also disappeared from 91 percent of their historic range.
Researchers suggest stricter limits on the number of cars allowed near the animals. Growth rates for cheetahs inside the protected areas need to be high if they are to make up for declines outside of them.
1. What is the text mainly about?| A．Cheetah numbers halved. |
| B．Conservation has a positive effect， |
| C．Tourism reduced cheetah numbers, |
| D．Tourists are not allowed to get close to cheetahs. |
| A．Because the birth rate is low, |
| B．Because hunman hunt them cruelly. |
| C．Because their habitat is reduced. |
| D．Because they have poor food supplies. |
| A．Disappointed | B．Worried. |
| C．Satisfied. | D．Shocked. |
| A．Set more preserves. | B．Stop hunting cheetahs. |
| C．Give cheetahs more food. | D．Limit cars near cheetahs. |
4 . A shocking 53.6 million tons of electronic waste were discarded（丢弃）last year, a new UN-backed report has revealed. The report shows that e-waste is up 21%from five years ago. This isn't surprising, considering how many more people are adopting new technology and updating devices regularly to have the latest versions, but the report also shows that national collection and recycling strategies are nowhere close to matching consumption rates.
E-waste contains materials including copper（铜）, iron, gold and silver, which the report gives a conservative value of $ 57 billion. But most are thrown away or burned rather than being collected for recycling. Precious metals in waste are estimated to be worth $ 14 billion, but only $4 billion-worth is recovered at the moment.
While the number of countries with national e-waste policies has grown from 61 to 78 since 2014, there is little encouragement to obey and a mere 17% of collected items are recycled. If recycling does occur, it's often under dangerous conditions, such as burning circuit boards to recover copper, which "releases highly poisonous metals" and harms the health of workers.
The report found that Asia has the highest amounts of waste overall, producing 24.9 million metric tons (MMT), followed by Europe at 12 MMT, Africa at 2.9 MMT, and Oceania at 0.7 MMT.
But whose responsibility is it? Are governments in charge of setting up collection and recycling points, or should companies be responsible for recycling the goods they produce? It goes both ways. Companies do need to be held accountable by government regulations and have incentives to design products that are easily repaired. At the same time, governments need to make it easy for citizens to access collection points and deal with their broken electronics in a convenient way. Otherwise, they may turn to the easiest option-the landfill.
1. What can we learn from the first paragraph?| A．What e-waste refers to. |
| B．Where e-waste is collected. |
| C．Why e-waste is increasing rapidly. |
| D．How many kinds e-waste includes. |
| A．The functions of policies. |
| B．The great damage to environment. |
| C．The change of consumption rates. |
| D．The urgency of recovering e-waste. |
| A．It does harm to the workers' health. |
| B．It lacks national policy support. |
| C．It hardly makes profits. |
| D．It takes too much time. |
| A．New technology should be used to update old devices. |
| B．Governments and companies should take responsibilities. |
| C．Non-poisonous metals had better be used in e-device. |
| D．Citizens must play a key role in recycling e-waste. |
5 . The Tibet autonomous region has placed nearly half its land area under the strictest ecological supervision (监督).It was announced at an annual meeting of the regional People's Congress, which kicked off on Wednesday.
The ecological protection area, which covers more than 539,000 square kilometers, makes up 45 percent of the region's area, and 22 ecological reserves have been built and are operational.
According to the government work report, the rate of days with good air quality in Tibet's cities has reached 99.4 percent, and all the region's drinking water sources have met applicable standards.
The report also said that the number of Tibetan antelope (羚)in the region has risen to more than 200,000, wildlife species to 1,072 and black-necked cranes to more than 8,000. Five rare new species have been discovered in recent years. The region has spent 12.2 billion yuan ($1.9 billion) on ecological protection projects in recent years. Five cities and three counties have been named as national-level ecologically civilized model cities and counties, and more rural residents have benefited financially by undertaking part-time ecological protection work.
More advanced monitoring facilities have been in place in the reserve, with more ecological protection inspectors employed to undertake protection work. The professional ecological inspectors are provided with basic tools such as motorcycles, telescopes and paging receivers, and they provide feedback regularly. Professional inspectors also receive one week of training every year from professors at Tibet University.
Kunsang Darje, a railway maintenance worker in Nagchu, said that apart from maintaining the railway and highway, he also collects trash along the section with his colleagues. “The place I work is in a no-man's land, and I think it's very important to protect the animals there without affecting them with human activities, and we are also bound to take responsibility there," he said.
1. What is the main idea of the text?| A．The ecological situation in Tibet has been totally improved. |
| B．Almost half Tibetan land has been ecologically supervised. |
| C．Many more operational ecological reserves have been built. |
| D．More Tibetan protection inspectors have been employed. |
| A．Larger protection areas. | B．Numerous rare new species. |
| C．More days with quality air. | D．Global capital investments. |
| A．protection inspectors can employ other people |
| B．protection inspectors are supplied with cars |
| C．Tibet's rural residents can get annual training |
| D．Tibet's rural residents can earn extra money |
| A．He asks his colleagues not to litter everywhere. |
| B．He attaches importance to raise animals there. |
| C．He keeps railway and highway in good condition. |
| D．He has a sense of duty to protect animals there. |
6 . A recent study suggests that vitamin D pills can help speed up the time taken for burns to heal, and prevent scarring(结疤). The vitamin, which is produced naturally in the body when the skin is exposed to sunshine, is believed to help protect against burning.
Previous studies have shown that vitamin D pills help decrease redness and swelling after sunburn, and may be one of the reasons why the body produces the chemical.
The research from Birmingham University, has found they may also help relieve other types of burn. Researchers monitored 38 patients who had suffered serious burns for a year and recorded their levels of vitamin D. They found that those with the highest levels of vitamin D had better wound healing and fewer scars.
Professor Janet Lord said: “Low vitamin D levels were associated with worse results in burn patients including life-threatening infections(感染),death and delayed wound healing. Major burn injury severely reduces vitamin D levels and adding this vitamin back may be a simple, safe and cost-effective way to improve the condition for burn patients.” Professor Lord and her team are now focusing on finding out why there is a rapid loss of vitamin D in patients immediately following burn injury and hope that they may be able to prevent this in future.
The amount of reduction in patients’ vitamin D levels was not related to the severity(严重程度) of the burn, so levels may also be decreased in minor burn injury, suggesting taking vitamin D pills could also help people with everyday burns. Public Health England now recommends that all Britons take vitamin D pills in the winter because it is impossible to make sufficient quantities in the darker months.
1. What does the new study find?| A．People with low vitamin D levels get burned easily. |
| B．Vitamin D helps with the recovery from burn injury. |
| C．Vitamin D pills aid in reducing the swelling from burns. |
| D．Vitamin D is more beneficial to serious burns than minor burns. |
| A．The severity of one's burn reflects his vitamin D levels. |
| B．Vitamin D pills are more needed in the autumn months. |
| C．Burn patients lacking vitamin D are at high risk of infection. |
| D．Minor burns have no effect on patients’ vitamin D levels. |
| A．The researchers. | B．Vitamin D pills. |
| C．Previous studies. | D．Some kinds of vitamins. |
| A．Vitamin D: A Necessity for Our Health |
| B．Vitamin D Pills: When Are They Needed? |
| C．Vitamin D: How Much Does the Body Need? |
| D．Vitamin D Pills: Heal Burns &. Prevent Scarring |
7 . Faced with a declining population and workforce, Japan has been increasingly turning to robots for help. Over the years, the robots have carried out a large number of human tasks, including building products and providing care for the elderly.
However, the robots currently being used by companies, like Walmart and Amazon, are only able to perform single, repetitive tasks, such as stacking boxes. Model-T, on the other hand, has a wider range of movement and is able to hold, pick and place objects of several different shapes and sizes into different locations, making it ideal for convenience and grocery stores, which sell a large variety of items.
Model-T robots are operated from a distant location by human “pilots” wearing a virtual reality (VR) headset and special gloves, which allow them to feel the product the robot is holding in their hands and guide it to the right shelf.
The VR-controlled robots are ten times cheaper than automated robots, because they don’t require advanced programming and are easier to develop and maintain. And their easy-to-use controls require little training. Tomohiro Kano, a general manager in charge of development at FamilyMart, believes this will enable the chain to recruit workers who would typically not work in stores.
Though Model-T appears to be getting rapidly through the experiments, it is not quite ready to enter the workforce. Besides being a lot slower than humans, it is also only able to lift packaged items, and cannot get hold of things such as fruits and vegetables. The company is working to improve the weaknesses and hopes to introduce a faster, more skillful Model-T within the next two years. They believe that in addition to the stores, the robots could also be useful in hospitals, allowing doctors to do operations from remote locations.
1. What is one of the features of Model-T according to the text?| A．It works much faster than humans. | B．It can easily hold all kinds of objects. |
| C．It can be operated from a distance away. | D．It is harder to produce than an automated robot. |
| A．The low price of Model-T. | B．The easiness to operate Model-T. |
| C．The low-level programming of Model-T. | D．The strict training for maintaining Model-T. |
| A．Model-T is now being massively produced. |
| B．Japan’s workforce will be reduced by Model-T. |
| C．The weaknesses of Model-T have been overcome. |
| D．Model-T may be used in wider fields in the future. |
| A．Technology. | B．Economy. | C．Lifestyle. | D．Environment. |
8 . One day, Amanda was diagnosed (诊断) with cancer of an early stage. During this time, she was admitted to a college. She planned to save money to meet the college expense and then seek medical treatment for the cancer.
Her father, Clint and her friends didn’t want her to put off her treatment due to the expense. They took matters into their own hands and started a GoFundMe campaign. A longtime friend of the family was cofounder of a group named Praynksters, known for random acts of kindness. The friend decided to use their own group to help the family. The group came up with the creative idea to spread the word and invite families, friends, and strangers who wanted to help to take part in a donation activity. The event induced the enormous assistance from the local community.
Clint and Amanda were moved as the crowd passed by and the donations poured in. The event brought the family over $13, 000 in donations to go towards her medical treatments. The generous act of kindness gave the family a comforting, and optimistic feeling during a time when all hope seemed lost. Clint said that Amanda struggled with the idea of asking for help. She felt guilty and undeserving compared to others who are also struggling. She is still humbled by it all.
After several months of treatment, life for the family has started getting back to their normal routine. Once Amanda got her strength back, she returned to school and completed her bachelor's degree. The family is now inspired to volunteer in their local neighborhood and contribute to crowdfunding (众筹) efforts. They are grateful for the opportunity to give back and help others as many have helped them.
1. Why did Amanda postpone her treatment of cancer?| A．She didn't care about her disease. |
| B．She had to take care of her family. |
| C．She was in a bad economic situation. |
| D．She couldn’t find an effective treatment. |
| A．Brought about. | B．Made up. |
| C．Gave away. | D．Set about. |
| A．Shameful but caring. |
| B．Kind-hearted and grateful. |
| C．Curious and warm-hearted. |
| D．Hard- working and humorous. |
| A．It's quite easy to cure Amanda’s cancer. |
| B．Praynksters is a nonprofit organization funded by Clint. |
| C．Volunteering is very popular in Amanda's community. |
| D．A GoFundMe campaign is actually a crowdfunding activity. |
9 . Have you ever noticed that the stars sometimes appear brighter in December, January and February? There's a link between cold air and the night lights. "Part of it is that it tends to be drier in the winter," said Diane Tumshek, an astronomer at Carnegie Mellon University in Pittsburgh, Pennsylvania. Even though it's invisible, moisture can change the way light moves through the air. And in the summer, moisture can make stars appear more dull.
Air temperature is also what puts the twinkle twinkle in the little stars. "Even on very clear nights, some of the atmosphere is cooler, and some of the atmosphere is warmer,” said Tumshek, who also works with the Allegheny Observatory. And when the light from a star passes through those bubbles of varying temperatures, "it bends and shifts the light, so that we are seeing stars appear to dance or twinkle,” she said.
For star lovers in the United States, there's another factor that comes into play for bright winter stars, although this is a matter of coincidence. During Earth's journey around the sun, “there are just simply more bright stars visible from the Northern Hemisphere in the winter sky," Tumshek said. If you really want to see a shiny star, just try to find a burning ball of gas called Sirius near the horizon. At 8.6 light-years away, Sirius is relatively close to Earth and the brightest star visible in the night sky. It is also large — nearly twice as big as our sun and 20 times as bright. So this winter, when the world turns cold and it seems like we should be spending more time indoors, consider asking an adult to go exploring outside. With a warm coat and a clear sky, any night can be turned into a treasure hunt. All you have to do is look up.
1. What does the underlined word "dull" in Paragraph 1 probably mean?| A．not shiny | B．not exciting | C．not severe | D．not smart |
| A．By changing the bubbles around them. | B．By putting the twinkle twinkle in them. |
| C．By varying the direction of the light from them. | D．By making the stars dance and twinkle in the sky. |
| A．It can be found at any night. | B．It is 20 times as bright as the sun. |
| C．It is a burning and shiny ball. | D．It is closer to Earth than other stars, |
| A．To advocate stargazing in winter, | B．To call on people to focus on stars. |
| C．To present new research results about stars. | D．To explain why stars are more visible in winter. |
10 . Amsterdam,the capital and most populous city in the Netherlands，is one of the most popular travel destinations in the world，famous for its beautiful canals，top art museum，cycling culture，and Red Light District.Here are some of the key points to remember as you plan your trip to Amsterdam.
Must-See AttractionsMost visitors begin their Amsterdam adventure in the Old Centre,which is full of traditional architecture，shopping centers,and coffee shops.You’ll also want to check out Amsterdam’s Museum Quarter in the South District，which is great for shopping at the Albert Cuyp Market and having a picnic in the Vondelpark.The top museums to visit are the Rijksmusuem,the Ann Frank House,and the Van Gogh Museum.The Canal Ring is a UNESCO World Heritage Site that was originally built to attract wealthy home owners and is a popular place for celebrity spotting and nightlife today.
TransportationTravelers should be aware that Amsterdam Airport Schiphol is one of the busiest airports in the world.This airport is located about 15 kilometers southwest of city center.You can catch a train from Schiphol to Amsterdam Central Station，which has many connecting routes.It’s typically not a good idea to drive a car to the city center because traffic is heavy and parking is difficult to find.Cycling is incredibly popular here,and it’s easy to find cheap bike rentals around town.Amsterdam has a flat terrain(地形) and is a great city to explore on foot.
Money Saving TipsUnless you really want to see the tulips(郁金香) blooming，avoid booking between mid-March and mid-May.This is when hotel and flight prices rise.
Look for accommodations in Amsterdam’s South District，where rates are generally cheaper than in the city center.Buy train tickets at the machine instead of the counter to save a bit of money.
Instead of hiring a tour guide，hop on a canal boat.They’re inexpensive and will give you a unique point of view of the city.Check out our homepage to view price comparisons for flights,hotels,and rental cars before you book.
1. Which attraction was built with the original purpose of drawing the rich?| A．Albert Cuyp Market. | B．The Ann Frank House. |
| C．The Van Gogh Museum. | D．The Canal Ring. |
| A．The plane. | B．The train. |
| C．The car. | D．The bike. |
| A．Seeing the tulips blooming in spring. | B．Avoiding accommodating downtown. |
| C．Buying car tickets at the machine. | D．Hiring a local tour guide. |
