1 . Bats are nature's pest hunter. Every night they fly out of their caves to enjoy millions of insects, including some harmful ones. But habitat（栖息地）loss and climate change, as well as infectious diseases are preventing them from doing their job. A new study adds another item to the list wildfires. But not too many—too few.
In California's Sierra Nevada, bats have adapted to occasional fires. But a century of fire-suppression（抑制）policies has kept some areas unburned for long periods, resulting in thicker forests and undergrowth. "We wanted to see how these changes might be influencing bat biodiversity." says ecologist Zack Steel in University of California, who conducted the research.
Steel and his colleagues tracked bats for over four years at six spots in Sierra Nevada. Three of the areas had been recently hit by wildfires, and three remained unburned.
Seventeen bat species call these forests home. The study revealed that eight of them tended to frequent the unburned areas, whereas 11 used the burned areas（some species visited both）. "We expected to see one group of species benefiting from fire—the more open-habitat-adapted species—and another group to be negatively affected by fire and prefer the unburned areas," Steel says. "But even some of those species were occurring more often in burned areas.”
What is ideal, the researchers write, is a combination of unburned areas and ones burned at different levels of severity. The results were published last December in the journal Scientific Reports.
"When there are changes in habitat after a fire, many species benefit in different ways," says University of Connecticut biologist Andrew Stillman. "On the whole, the community becomes more diverse, and that's a good thing for the landscape.”
Extinguishing wildfires early leads to some species losing out on food and resources. "Fire is a natural part of the ecosystem, and many animals require the disturbance from fire to create the types of habitat that they need," Stillman adds. "It shows another negative consequence of keeping wildfire away from fire-adapted forests in California."
1. What can we learn about the research from the text?| A．The researchers kept track of the bats for six years at four spots. |
| B．11 bat species visited both of the burned and unburned areas. |
| C．The result of the study was out of the researchers' expectation. |
| D．The unburned areas were preferred by most of the bat species. |
| A．Stopping. | B．Observing. |
| C．Causing | D．Catching. |
| A．Negative. | B．Positive. |
| C．Cautious. | D．Doubtful. |
| A．California Forests | B．Bush Fires |
| C．Burn Benefits | D．Bats' Habitats |
2 . An Australian couple has been rescued from a crocodile-ridden part of Australia's remote north after lighting a fire and writing the word "help" in mud to attract the attention of search crews.
Colen Nulgit, 20, and his girlfriend Shantelle Johnson, 18, went fishing on Sunday in Keep River National Park near Western Australia. There are saltwater crocodiles in all waterways around the park.
Nulgit said their day of fishing tuned into a freezing, sleepless overnight stay when their truck got stuck in mud. "Our hearts sank," Nulgit said, Nulgit said they had seen crocodile tracks in the area earlier and, as the waters rose and sun set, because afraid of being swept away by a large tide—or being attacked by crocodiles. "These crocodiles are not afraid of humans. They're not afraid of anything." he said. "Food's food for them. Anything is food."
In their home town of Kununurra, Johnson's mother called the police when they failed to return that night. Nulgit said they huddled(蜷缩) under a blanket away from the river, but couldn't get any sleep. They wrote "help" in large letters in the dry mud with a stick at about 4 a. m. Monday, hoping to attract attention from a passing plane. However Nulgit admitted he was worried about being stranded for a long time, adding: "Hardly anyone goes out that way."
On Monday, Kununurra police organized a search party using a plane from a local company to find the pair, the Western Australia Police Force said in a statement. Nulgit and Johnson lit a fire as soon as they heard the plane to help draw attention.
"If they had not lit the fire and advised family members details of when they were leaving and an expected return time, the couple may not have been located," the police statement added.
Nulgit said the adventure wouldn't stop the pair from heading out again—although next time they'll make better preparations beforehand. "I'm just grateful for everyone who helped and came out to look for us," he said. "We're pretty lucky surviving and getting out of that."
1. What is the text mainly about?| A．The danger from crocodiles. | B．A young couple's adventure. |
| C．The Australian police force. | D．A sleepless night by the fire. |
| A．Trapped. | B．Attacked. | C．Ignored. | D．Swept. |
| A．frightened | B．annoyed | C．depressed | D．regret |
| A．The couple wrote the word "help" in mud with a stick. |
| B．The couple huddled under a blanket the whole night. |
| C．The couple told Johnson's mom when they would return. |
| D．The couple gave a detailed description of their location. |
3 . Every year, companies like GoPro manage to pack more and more functions into smaller and smaller action cameras that are less noticeable to wear. But a team of researchers from the University of Washington have managed to build a live-streaming wireless camera that’s so small that even an insect can wear it. It’s not quite small and light enough to be held to a fly, but at around 250 milligrams, the camera was successfully carried by a beetle.
Although the camera inside a modern smartphone is certainly tiny, it’s too large and heavy for an insect to carry once the batteries are added. Capturing millions of pixels（像素）with every shot requires a lot of image processing, which in turn requires a lot of power. Taking an alternate route, the researchers copied nature’s approach to how flies see the world. Their large compound eyes can not only detect motion across a wide field of view（it’s why they’re so difficult to hit）but also feature a small, high-resolution（分辨率）region that can focus on their targets, which helps reduce the load on their tiny brains.
Given its size and low-power approach, the camera’s streaming abilities are similarly limited, with a Bluetooth connection that maxes out at a distance of roughly 120 meters, requiring a remote operator to be fairly close to the camera at all times. However, battery life is surprisingly decent. The camera can run for up to two hours, but to extend that, the researchers included an accelerometer so that it’s only capturing and broadcasting images whenever the beetle is moving That can increase the camera’s battery life to over six hours.
The researchers acknowledge that their design certainly raises some privacy concerns, given how easy it is for insects to find their way into your home. But the camera could provide entomologists（昆虫学者）with new insights into how insects cross their environment, respond to threats in the wild, and even provide a closer look at their social structures.
1. What is the feature of the new camera?| A．It’s small-size and low-weight. | B．It takes much clearer pictures. |
| C．It can perform tasks in the open air. | D．It protects beetles from their enemies. |
| A．How to enlarge its vision. |
| B．How to capture the target. |
| C．How to save power of its battery. |
| D．How to make sharp turns during flying. |
| A．casual | B．adequate | C．beneficial | D．unsatisfactory |
| A．Critical. | B．Doubtful. | C．Favorable. | D．Objective. |
4 . To move visual technology into the future, sometimes it helps to make a little noise. Researchers have used sound waves to produce floating 3-D images, create a sense of touch and even supply a soundtrack.
Since the 1940s, scientists have toyed with the concept of acoustic levitation(声悬浮), the use of soundwave vibrations(震动) to trap tiny things in midair. The technology has gained greater capabilities in the past decade. Some researchers believe this improvement could lead to applications such as contributing to novel 3-D printing methods, or creating displays that would be visible from any angle without requiring a screen.
Other researchers have also worked on visual displays that use acoustic levitation. In addition to visuals, the system can also produce audible noise to give the display a soundtrack. And the ultrasound speakers can also concentrate vibrations in one spot so that a finger might feel a sense pushing back—a little like the object shown by the floating image is really there. Soundwaves create a 3-D display!
Display without a screen is remarkably useful. It means that everybody in the room can see the image—any angle, location—and that’s extremely helpful. As a communications system, such a display might one day allow users to chat with a 3-D projection(投影) of a person who can turn his or her head to follow as they move around a room.
The display will require a lot more work before you can install it in your living room, however. So far, this has been done in the research laboratory. We need to push it a little bit harder. We need to do more analysis to see if it would make sense to create a real display that people would have at home. The current system can only show simple graphics, such as a smiley face or figure eight, in real time.
Still, we are optimistic about the potential for this type of technology. If the system had only one speaker-covered surface instead of two, it could generate images that are bigger than the device itself. We can’t make a TV image that’s bigger than the TV—even a projector has to have a projection screen that’s bigger than the image itself. But with a volumetric(容积的) display, a small, portable device might produce a much larger picture. We can imagine, in the future, having volumetric displays in watches, for example, that create large images that just project out of your watch.
1. From the first two paragraphs soundwave vibrations can be used to _________.| A．catch very small objects in midair |
| B．develop 3-D printer’s capabilities |
| C．replace a creative display screen |
| D．compose soundtracks by making no noise |
| A．Different. | B．New. | C．Storied. | D．Formal. |
| A．Room for the technical improvement. |
| B．Situations of the modern technology. |
| C．Praise for the cutting-edge technology. |
| D．Outlooks for the new technology. |
| A．Hearing is Seeing—Sound Waves Create a 3-D Display. |
| B．Seeing is Believing—3-D Printing Methods Arrive. |
| C．Advancing Sense of Touch—3-D Images Float in the Air. |
| D．Promoting TV Technology—Chat with 3-D Projections. |
5 . Fertile Sichuan has long been one of China's major tea- producing regions. Chengdu had been noted for its teahouses by the Tang dynasty—as early as the ninth century. For centuries, teahouses were places for entertainment as well as tea, with performances of storytelling, music, and Sichuan opera in particular. That is a fading art these days, but Yuelai Teahouse beside Jinjiang Theater still hosts opera every Saturday afternoon.
You will find most of Chengdu's old-school teahouses in parks and temple compounds (大院). Heming Teahouse in Renmin Park buzzes with morning retirees, lunchtime office workers, and afternoon visitors. All of them sit under red lanterns by a lotus pond. When the loud confused noise gets too much, move on to Shaocheng Teahouse in the same park. Regulars are older and quieter. They bring songbirds on outings, hanging their cages in the branches of willow trees, and play mahjong in a pavilion covered with moss. In more recent years, however, increasingly elaborate(精致的) teahouses have opened to appeal to the younger generation. They tend to have a taste for superior teas in a more contemporary style. The most famous one of them is Mi Xun Teahouse in Taikoo Li, which is right in the city's most fashionable retail(零售) district.
As in all teahouses, the tea comes in individual packets with a thermos of water. Maofeng green tea from Mount Emei, south of Chengdu, is the traditional favorite. Shake the loose leaves into your palm-sized cup. The cup usually comes with a saucer and a lid that both functions to strain surface-floating leaves and to keep the tea warm. Don’t let the water level in your cup get too low, since any bitterness from the tea leaves is concentrated at the bottom. You can top up your tea all afternoon and needn't buy anything else.
1. What aspects of Chengdu's teahouses does the first paragraph mainly focus on?| A．Art & history. | B．Art & popularity. |
| C．Function & popularity. | D．History & function. |
| A．Tourists. | B．Owners. | C．Customers. | D．Waiters. |
| A．Yuelai Teahouse. | B．Mi Xun Teahouse. |
| C．Heming Teahouse. | D．Shaocheng Teahouse. |
| A．Some useful tips for readers who want to visit Chengdu's teahouses. |
| B．Some interesting facts the author found in books on Chengdu's teahouses. |
| C．Some painful lessons the author learned from his trip to Chengdu's teahouses. |
| D．Some basic rules readers have to follow if they want to visit Chengdu's teahouses. |
| A．To experience Chengdu's everyday life. |
| B．To introduce Chengdu's teahouse culture. |
| C．To stress the advantages of a slower pace. |
| D．To inspire readers to travel to Sichuang. |
6 . Innovations are not always welcome. In 1589 William Lee made his way to the English court, hoping to be granted a patent for his invention, a knitting machine. Queen Elizabeth I turned him down: "Consider what the invention could do to my poor subjects," she commanded. "It would assuredly bring ruin to them by robbing them of employment."
The fears of Good Queen Bess have echoed down the centuries—from the Luddites, who destroyed textile machinery in the early 19th century, to John F. Kennedy, who warned of the dangers of automation during his presidential campaign of 1960. In the 21st century the concerns have switched to robots and artificial intelligence (AI); 30% of American workers believe their jobs are likely to be replaced by robots and computers in their lifetime
In the past the relationship between machine and human labor has been driven by two factors: the substituting effect, which caused people to lose jobs, and the complementing effect, which allowed employees to do their work more productively. Mr. Susskind worries that, in the future, the substituting effect will take over. Advances in Al have been so rapid that machines will eventually be better than people at most activities, he says, and so will be the "default（默认）choice" for performing them. A few highly paid humans will still be employed, but the rest will either struggle to find work or fall into the "precariat", stuck in jobs that are not just poorly paid but also unstable and stressful.
This depressing view of the impact of technology is plausible（貌似有理的）. But so is a more optimistic outlook, as the economist Roger Bootle showed in his book. Mr. Bootle argued that Al and robotics would improve productivity and economic growth, and release people from performing the most lengthy tasks. As for employment, there will always be demand for services with the human touch. Perhaps, the truth is that it is impossible to be sure whether the latest advances will in the end have mainly good or bad economic effects.
1. What's the purpose of the examples in Paragraphs 1 and 2?| A．To tell people how many inventions are made. |
| B．To remind people how important the machines are. |
| C．To demonstrate the possible dangers to human beings. |
| D．To show some people's attitude towards new inventions. |
| A．People who have stable jobs. | B．People who like their jobs. |
| C．People who are stuck in bad jobs. | D．People whose jobs are well-paid. |
| A．Positive. | B．Negative. | C．Neutral. | D．Indifferent. |
| A．The impact of technology is depressing. |
| B．He showed a pessimistic attitude to technogy in his book. |
| C．AI and robotics would harm productivity and economic growth. |
| D．AI and robotics release people from performing long and tiring tasks. |
7 . China launched a large robotic spacecraft on Nov. 24, 2020 at the Wenchang Space Launch Center in South China's Hainan province, tasking it with landing on the moon and bringing back lunar samples, 44 years after the last time such substances were brought back to Earth.
If everything proceeds smoothly, about 2 kilograms of stones and soil will be collected and packed in a vacuum metal container. The entire mission is scheduled to last about 23 days, according to the China National Space Administration. Considering these highly sophisticated operations, Chang'e 5 will be more difficult and challenging than previous Chinese lunar expeditions, designers have said.
According to a statement published by the space administration, the Chang'e 5 mission is intended to fulfill several objectives. In terms of space engineering, it will demonstrate technical plans and apparatus for autonomous lunar sampling and packing and moon-based launching, as well as lunar orbital docking. In the scientific field, it will investigate the landing site's features, and enable scientists to analyze the lunar samples' structure and physical traits so they can deepen their research into the moon's origin and evolution. It added that the mission also will help to foster the country's knowledge, technology and talent pool for its future manned missions to the moon and other deepspace expeditions.
Pei Zhaoyu, spokesman for the Chang'e 5 mission, said if the mission becomes successful, it will be a milestone in the nation's lunar exploration and will show the world China's scientific, technological and engineering capabilities.
Furthermore, Chang'e 5 will strengthen the nation's status and influence in the international space community, pave the way for the country's future lunar expeditions and boost its space science, and will offer more opportunities to lunar researchers around the world. Scientists around the world are welcome to participate in the research related to the lunar samples brought back by the mission. China will publish a set of guidelines about the use and distribution of the samples after the mission.
1. What can we learn about the mission of Chang'e 5?| A．It was exactly the same as 44 years ago. |
| B．It will help to complete space walking. |
| C．It aims to bring back lunar samples. |
| D．It will try to land on the moon for the first time. |
| A．impossible | B．complex |
| C．ambitious | D．effective |
| A．The first nation to bring lunar samples back in the world. |
| B．A further step in understanding the evolution of the earth |
| C．More competition in lunar expeditions with other countries. |
| D．China's scientific, technological and engineering abilities. |
| A．The landmark mission of Chang'e 5. |
| B．A new guideline from the moon samples. |
| C．New opportunities to lunar researchers |
| D．China's scientific contributions. |
8 . If businesses are to get workers back into the office during the epidemic(疫情) period, finding ways to maintain social distancing will be key. An Israeli company thinks it can help, using smart sensors mounted on workplace ceilings(天花板).
PointGrab developed its technology before the epidemic to help workspace managers optimize(优化)how employees use office space. About the size of smoke alarm, the sensors can record the exact number and location of people in buildings including offices, hotels and restaurants.
One of the company's first customers was Deloitte, which installed the system at its flagship London office last year. PointGrab's sensors were connected to screens in the building to show the availability of desks and shared areas in real time. PointGrab CEO Doron Shachar says it was one of a range of innovations that helped Deloitte fit 30% more people into 3% less space.
Now PointGrab has adapted the technology so the sensors can also monitor social distancing by keeping track of how far apart people are, and whether they're traveling in one direction around a building.
Workspace managers can set up warnings for when two people are closer than two meters for more than 30 seconds, for example.
The sensors have been included in the “six feet office” concept created by real estate(房地产) services company Cushman and Wakefield to encourage employees to practice social distancing. They are currently being used in this way at a university in the Netherlands, and at an innovation hub in Belgium.
While the social distancing innovation is new, PointGrab has deployed ( 部署)more than 10,000 sensors for workspace optimization, including in the offices of Coca-Cola, Facebook and Dell.
Workers might not like the idea of being monitored, but PointGrab says no images or identifying features are recorded. Instead, each employee is represented as an anonymous(无名的)dot on a dashboard.
“The sensor does respect people's privacy,” Shachar says. “This is extremely important the workspace.”
1. Which world can replace “mounted” in the first paragraph?| A．adapted | B．connected | C．fixed | D．included |
| A．make the best of employees' office space |
| B．keep track of how far apart employees are |
| C．encourage employees to practice social distancing |
| D．monitor people's privacy |
| A．Smart sensors can help save more space. |
| B．People will be warned when they are too closer. |
| C．Smart sensors will be installed in the offices of Facebook. |
| D．People's privacy can be recorded clearly. |
| A．Smart sensors will help maintain social distancing. |
| B．Getting workers back into the office is not easy. |
| C．How an Israeli company develop smart sensors. |
| D．Social distancing is extremely important in the workspace. |
9 . Have you ever wondered why certain pop songs just make you feel so good? Researchers studying the question found that uncertainty and surprise give listeners the most pleasure. The study included 80,000 chords（和弦）in 745 pop songs between 1958 and 1991.
Each song was stripped of its melody（旋律）and lyrics（歌词）so that only chords were left and the results couldn’t be misunderstood by other imaginations of the songs that listeners might have had.
They found two things. Listeners got great pleasure from unexpected chords when they knew what would happen. However, they still found it pleasant to hear familiar chords when they did not know what would follow.
Vincent Cheung, the lead researcher, said, "Pleasant songs are likely those which keep a good balance（平衡）between knowing what is going to happen next and surprising us with something we did not expect. Understanding how music starts our pleasure system in the brain could explain why listening to music might help us feel better when we are feeling blue.”
Cheung told CNN that pleasure in music is connected to expectation. The study before had looked into the effects of surprise on pleasure, but his team's study also paid attention to the uncertainty of listeners' expectations.
1. What does the underlined word in Paragraph 2 mean?| A．Removed. | B．Added. |
| C．Played. | D．Recorded. |
| A．They listened to lots of pop songs. |
| B．They focus on the chords in popular songs. |
| C．They imagined the songs that can make people pleased. |
| D．They found lots of songs and then compared each other. |
| A．Pleasant music can explain human nature. |
| B．Listening to music might make people feel blue. |
| C．Music can improve the pleasure system of people. |
| D．Pleasant music comes from the balance of expectation and surprise. |
| A．His study only paid attention to chords in songs. |
| B．His study focused on the effects of surprise on pleasure. |
| C．His study took time to how music starts the pleasure system. |
| D．His study paid attention to the uncertainty of listeners' expectations. |
10 . Most polar bears could disappear by the end of the century, scientists say. Global warming is to blame. According to a study published this month in Nature Climate Change, most polar bear populations will be in serious decline by 2080. The cause is melting sea ice.
Polar bears hunt seals on the ice. Without ice, the bears must wander on the shore, where they are spending more and more time away from their main food source. That means the animals could starve.
“There’s not enough food on land to sustain a polar bear population,” Péter K. Molnár told the New York Times. He is the study’s lead author.
Lack of food leads to another problem: Mother bears may not be fat enough to produce milk for their cubs. Some bear populations could stop having babies, leading to a rapid decline in numbers.
Arctic sea ice usually melts in the spring and summer, then grows in the winter. But now, the ice is taking longer to grow back. Weather statistics say the Arctic is warming twice as fast as the rest of the planet. Ice in the region has declined 13% every 10 years since the 1970s.
The Arctic is home to roughly 25,000 polar bears. Scientists have long known that the animals are in danger. This study, which looked at 13 of the world’s 19 polar bear populations, is the first to identify when they could disappear.
But the study also notes that it is still possible to slow Arctic melting. The world can reduce the burning of fossil fuels and lower the greenhouse gas emissions that contribute to climate change. It would have to be a drastic reduction. Bringing emissions to only a moderate level will still mean the loss of some polar bears.
Saving the bears is up to us, Holland says. “I believe that there is hope,” she says. “But humans need to act quickly to turn that hope into a reality.”
1. Why are polar bears in danger of disappearing?| A．Lack of seals. | B．Global warming. |
| C．Less milk for cubs. | D．The loss of home. |
| A．Reduce. | B．Suffer. | C．Support. | D．Increase. |
| A．Doubtful. | B．Neutral. | C．Negative. | D．Positive. |
