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 . 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. |
4 . 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. |
5 . For Stevens Point locals in the US, the city is flooded with delicious fried fish. Here are four top choices for the community to have a try.
Hilltop Pub&Grill
Hilltop Pub&Grill first opened in the 1980s and took the Stevens Point community by storm with its delicious food and unique decoration style. Its fried fish are beloved due to the use of “high-quality North Atlantic fish, with a light beer batter (面糊)”.
The Final Score Bar&Grill
The Final Score Bar&Grill aimed to become a local hot spot in 2001 when Jim Billings, the owner, took charge of the business. Billings feels that their five batter choices set them apart from their neighboring bars. Besides, various wines are available.
Point After Pub&Grill
Point After Pub&Grill started serving delicious food and cold beers in a welcoming environment in 2009. But its history runs much longer. “Before it was Point After Pub&Grill, it had been Northside Bar for 30 plus years,” explained Molski, the owner. Molski feels that the pub’s four special batter choices and other fish specials are what help make it an area landmark.
Two Harps Pub
This Irish pub opened its doors to the public in 2017 and has been drawing fans and locals ever since. “I had done my career for a long time and was kind of bored with it,” said Nick Moore, the owner. “And this opportunity fell into my lap, so I went with it. It really made sense to open up an Irish bar.” The growing pub advises guests to try a cold beer with their Friday fried fish.
1. What makes Hilltop Pub&Grill popular with customers?| A．The convenient location. | B．The special food. |
| C．The high-quality service. | D．The unique wine. |
| A．They are both run by the same company. | B．They are both famous for great wines. |
| C．They both feature some particular batter. | D．They were both founded ten years ago. |
| A．It is the newest among the four pubs. | B．It offers free cold beers to customers. |
| C．It only provides fried fish on Fridays. | D．It has a unique decoration style. |
6 . He is regarded as having one of the brightest minds on the planet.But outstanding astrophysicist（天体物理学家）Stephen Hawking admitted that he did not learn to read until he was eight years old.In a public lecture at the Royal Albert Hall,Professor Hawking also admitted that he was not active in studying while at Oxford University,where he studied physics,and that only the diagnosis that he might die young from motor neurone（神经元）disease made him concentrate on his work.
Professor Hawking said,"My sister Philippa could read by the age of 4 and then she was definitely brighter than me."He said that he was unexceptional at school and was never further than halfway up his class."My classwork was very untidy,and my handwriting was the despair of my teachers,"he said."But my classmates gave me the nickname Einstein,so presumably they saw signs of something better."
But he said that it was when doctors told him that he probably only had a few years to live at the age of 21 that he was galvanized into focusing on his work and a period of productivity that resulted in some of his early breakthroughs.He said,"When you are faced with the possibility of an early death,it makes you realize that life is worth living and there are lots of things you want to do."
1. Which of the following is NOT true according to the passage?| A．Stephen Hawking is the second Einstein in the world. |
| B．Stephen Hawking couldn't read at the age of 7. |
| C．Stephen Hawking's handwriting was once terribly bad. |
| D．Stephen Hawking's sister once performed much better than him. |
| A．Patience. | B．Knowledge. | C．Disease. | D．Laziness. |
| A．Stephen Hawking didn't realize his dreams in physics. |
| B．It was possible for Hawking to face the early death. |
| C．The purpose of the doctor's diagnosis was to encourage him to work hard. |
| D．His life might be taken away by long hard work. |
| A．His sister. | B．His classmates. | C．His teachers. | D．His parents. |
7 . There’s no doubt that one of the greatest human achievements is the exploration of the space. Ever since astronaut Yuri Gagarin became the first person to be sent into the orbit around the moon in 1961, scientists have been pushing the boundaries further and further. But until now the exploration into the unknown has been dominated (主导) by men.
Of course, in the past, women were also included in the space projects and played an active role on the ground and behind the scenes. For example, they worked as seamstresses (女裁缝师), sewing vital spaceflight components. In fact, many of NASA’s key works would never have been possible without them. Recently Hollywood produced a movie called Hidden Figures to focus on a group of American female mathematicians, especially the black women, who helped NASA send the first American into space. But this was not women’s only contribution. Back in 1963, Soviet astronaut Valentina Tereshkova became the first woman to be sent into space. However, after that, space flight programs were slow to employ women. In the USA. NASA didn’t accept applications from women to become astronauts until 1978.
But attitudes have changed and leading officials at NASA say that the first person to set foot on Mars should be a woman. The space agency aims to have a sex-balanced workforce but can only achieve that if equal numbers of men and women are trained for science and technology jobs. As Allison McIntryre told the BBC, “My director is a woman. We have female astronauts. We haven’t put a woman on the moon yet. And I think that perhaps the first person to step on Mars should be a woman.”
1. What did Yuri Gagarin do in 1961?| A．He landed on the moon in success. |
| B．He discovered many new boundaries. |
| C．He led scientists to explore the moon. |
| D．He made the first journey into the space. |
| A．To show women are the true heroes of NASA’s first launch. |
| B．To stress that black people have won equal rights in NASA. |
| C．To prove women can do as well as men in NASA’ projects. |
| D．To present women’s contributions to NASA’s space programs. |
| A．Uncaring. | B．Disapproving. |
| C．Supportive. | D．Disappointed. |
| A．Will the First Person to Step on Mars Be a Woman? |
| B．Great Achievements Have Been Made in Space Exploration? |
| C．Why Men Played an Important Role in Exploring the Unknown? |
| D．Men and Women Have Made Equal Contributions to NASA’s Projects? |
8 . As the world's resources become rarer because of continuing land development and the growing human population, the natural habitats of wild animals have continued to decrease. As a result, the survival of some species of wildlife is threatened. To help protect wildlife, a lot of practices should be carried out by environmentalist as well as the general public.
Create homes for species that are endangered because of losing their own natural habitats. Wildlife shelters should be developed, and habitats should be created in existing(现存的) national parks. Efforts(努力) should also be made to protect existing habits, such as providing food and water sources and limiting hunting. Breed(培育) endangered species in places such as zoos. Once the young animals grow up, they can be set free into the wild where they can continue to increase the population.
The general public may not realize that a species is endangered until it's too late. Educational programs making use of TV advertising and instructional meetings at national parks can be used to make the public know the situation.
The general public can help protect the wildlife by not hunting wild animals for sport or for a source of food. They should also stop supporting those who earn money from the illegal hunting of wild animals, such as hunters who kill animals for the only purpose of harvesting their body parts and selling them for money.
The public should avoid(避免) keeping wild animals as pets. This will limit the number of animals being tracked, trapped, sold and removed from their natural habitat.
1. Which of the following is not the measure of protecting animal habitats?| A．Developing wildlife shelters. |
| B．Creating new habitats. |
| C．Setting young animals free in the wild. |
| D．Protecting the existing habitats. |
| A．the general public may not know species are endangered. |
| B．many endangered species are facing the danger of extinction. |
| C．people can do much to protect the endangered species. |
| D．human activities can affect the existence of species. |
| A．some people hunt animals and sell them as pets |
| B．hunters get little money from hunting animals |
| C．general public do nothing about protecting the wildlife now |
| D．animal population becomes larger in the zoo |
| A．Environment. | B．Sports. |
| C．Technology. | D．Education. |
