【推荐1】A study suggests that the Arctic “may be essentially ice-free (不结冰) during summer within 15 years.”

The study used statistical models to predict the future amount of Arctic ice, which suggested that the Arctic could be ice-free in the summer during the decade of the 2030s---most likely in the year 2034.

Sea ice is frozen ocean water that melts each summer, then refreezes each winter. The amount of summer sea ice in the Arctic has been steadily shrinking over the past few decades because of global warming. It reached its second-smallest level on record in 2019, the National Oceanic and Atmospheric Administration (NOAA) said.

Sea ice affects Arctic communities and wildlife such as polar bears and walruses (海象), and it helps regulate the planet's temperature by influencing the circulation of the atmosphere and ocean.

"The extent of Arctic ice is important to Arctic people, whose lands are being affected by increased coastal erosion (侵蚀)"   NOAA said in a statement. "Conversely, the disappearance of ice creates economic opportunities, including the opening of oil fields and new shipping routes." It also affects global weather patterns.

The study was conducted by scientists at NOAA, the University of Washington, and the North Carolina Institute for Climate Studies.

What scientists refer to as the first "ice-free" Arctic summer year will occur when the Arctic has less than 1 million square kilometers of sea ice. The thick ice sheets surrounding Canada's Arctic islands are likely to remain for much longer, even in summer.

As the climate changes, the Arctic is warming more than twice as fast as the rest of the planet. Arctic air temperatures were about 3. 4 degrees above average in 2019. and were the second-warmest since records began in 1900.

Scientists also said the results of the study indicate that there is room for improvement in sea-ice models—and that the ice may disappear even more quickly than current models suggest.

"Climate models may be collectively underestimating the rate of change," the authors write in the study.

1. How did the researchers get the study results?

A．By what the arctic people said.

B．By statistic models.

C．By Watching from the universe.

D．By the video taken from the Arctic sea.

2. Why is the amount of summer sea ice becoming smaller over the past years?

A．Because the sea water becomes more salty.

B．Because people are opening oil fields there.

C．Because too many people are visiting the area.

D．Because it is becoming warmer globally.

3. The records of the amount of sea ice began                  years ago.

A．10

B．15

C．20

D．30

4. What does the underlined word "refreeze" in the third paragraph mean in Chinese?

A．再融化

B．重新崛起

C．再扩大

D．重新结冰

5. Which of the following is true according to the passage?

A．The disappearance of the sea ice brings no good to the world.

B．There will be more polar bears and walruses because of the ice-free climate.

C．"Ice-free" doesn't mean that there is no ice at all in the Arctic area.

D．The Arctic is warming as quickly as the whole earth.

【推荐2】A recent study, led by Professor Andrew Barron, Dr. HaDi MaBouDi, and Professor James Marshall, illustrates how evolution has fine-tuned honey bees to make quick judgments while minimizing danger.

“Animal lives are full of decisions,” says Professor Barron. “A honey bee has a brain smaller than a sesame (芝麻) seed. And yet it can make decisions faster and more accurately than’ we can. A robot programmed to do a bee’s job would need the backup of a supercomputer.”

Bees need to work quickly and efficiently. They need to make decisions. Which flower will have a sweet liquid? While they’re flying, they face threats from the air. While landing, they’re vulnerable to potential hunter, some of which pretend to look like flowers.

Researchers trained 20 bees to associate each of the five different colored “flower disks” with their visit history of reward and punishment. Blue flowers always had sugar juice. Green flowers always had a type of liquid with a bitter taste for bees. Other colors sometimes had glucose (葡萄糖). “Then we introduced each bee to a ‘garden’ with artificial ‘flowers’. We filmed each bee and timed their decision-making process,” says Dr. MaBouDi. “If the bees were confident that a flower would have food, they quickly decided to land on it, taking an average of 0.6 seconds. If they were confident that a flower wouldn’t have food, they made a decision just as quickly. If unsure, they took on average 1.4 seconds, and the time reflected the probability that a flower had food.”

The team then built a computer model mirroring the bees’ decision-making process. They found the structure of the model looked very similar to the physical layout of a bee brain. “AI researchers can learn much from bees and other ‘simple’ animals. Millions of years of evolution has led to incredibly efficient brains with very low power requirements,” says Professor Marshall who co-founded a company that uses insect brain patterns to enable machines to move autonomously, like nature.

1. Why does Professor Andrew Barron mention “a supercomputer”?

A．To illustrate how a honey bee’s brain resemble each other.

B．To explain how animals arrive at informed decisions fast.

C．To demonstrate how a robot could finish a honey bee’s job.

D．To emphasize how honey bees make decisions remarkably.

2. Which of the following can best replace “vulnerable to” underlined in paragraph 3?

A．Easily harmed by.	B．Highly sensitive to.
C．Deeply critical to.	D．Closely followed by.

3. What influenced the speed of trained bees in making decisions?

A．Their judgments about reward and punishment.

B．Their preference for the colors of flower disks.

C．Their confirmation of food’s presence and absence.

D．Their ability to tell real flowers from artificial ones.

4. What message does Professor James Marshall want to give us?

A．The power of bee brains is underestimated.	B．Biology can inspire future AI.
C．Autonomous machines are changing nature.	D．AI should be far more efficient.

【推荐3】Insects are a rich source of protein and part of the natural diet for pigs, chickens and fish. Feeding insects to farm animals could be the environmental change that the farming industry has been waiting for.

It takes around 2.5 acres of land to produce a metric ton (公吨) of soya beans each year, but the same area could grow nearly 140 metric tons of insects. Cutting back on beans for animal feed can also reduce the act of cutting down the trees, especially in areas like the Amazon rainforest, where trees are cut down to increase farmland.

Farm animals eat around one-third of global grain production, some of which could be used to feed people instead. Reducing land use and the crops fed to farm animals can change the global food system and makes it more sustainable (可持续的)，according to a United Nations report.

Besides, insects can be fed on food waste. And because they do not need much space, they can be raised on farms in small-scale units like small containers. A British company Better Origin packs its containers with food waste and insects, and then they grow up to 5,000 times their original body mass in just two weeks. Researchers have forecast that the amount of food going to waste will hit two billion metric tons globally by 2030. If that can be changed into insect feed for animals, it will make livestock (家畜) production cheaper and more sustainable.

Startup companies like Better Origin are joining a fast- growing market. US food giant Cargill has entered the sustainable insect feed market by partnering with InnovaFeed to supply fish farms with black soldier fly larvae (a kind of insect).

“It is time to think about alternative (可供替代的) sources of food in view of a growing world population,” said Eduardo Rojas-Briales, Chairman of the Spanish Board of Foresters. “Insects alone will not solve the world’s food security challenges but it would be absurd not to make use of their full potential in the fight against hunger.”

1. Why does the author list the figures in Paragraph 2?

A．To stress the high cost of insect feed.

B．To illustrate the importance of increasing farmland.

C．To present the situation of the Amazon rainforest.

D．To show the benefits of using insects as animal feed.

2. Which of the following can be inferred from the text?

A．Many trees are cut down to feed insects.

B．Only insects will solve the world’s food security challenges.

C．The growth of insects requires strict environmental conditions.

D．Feeding insects to farm animals does good to the global food system.

3. What does the underlined word “absurd” in the last paragraph mean?

A．Possible.

B．Unwise.

C．Selfish.

D．Intelligent.

4. Which is the most suitable title for the text?

A．Let’s make full use of farmland

B．How to reduce the amount of food waste

C．Insect feed can change the farming industry

D．How to improve the quality of livestock production

【推荐1】A method to transform a commonly thrown-away plastic to a resin (树脂) used in 3D- printing could allow for making better use of plastic waste.

A team of Washington State University researchers developed a simple and efficient way to transform polylactic acid(PLA), a bio-based plastic used in products such as plastic tableware and food packing to a high-quality resin. Yu-Chung Chang, a postdoctoral researcher on the work said they made stronger materials just straight out of waste, and they hoped that would provide people with the stimulation to upcycle this stuff instead of just throwing it away.

PLA is rarely recycled because like most plastics, when it’s melted down and reformed, it doesn’t perform as well as the original version and becomes less valuable.

“But once you look into it, it turns out that it can take up to 100 years for it to break down in a landfill,” Chang said. “In reality, it still creates a lot of pollution. We want to make sure that when we start producing PLA millions of tons, we will know how to deal with it. ”

In their study, the researchers developed a fast method to recycle PLA breaking the long chain of molecules (分子) down into simple monomers (单体)-the building blocks for many plastics. The entire chemical process can be done at mild temperatures in about two days. The chemical they used to break down PLA, aminoethanol, is also inexpensive.

“If you want to rebuild a Lego castle into a car, you have to take it apart brick by brick, Chang said. “That’s what we did.” Once PLA was broken down to its basic building blocks, the researchers rebuilt the plastic and created a type of liquid resin that is commonly used as printing “ink” for 3D printers. When used in a 3D printer and cured into plastic pieces the product was equal or better than commercially available resins.

The researchers have applied for a temporary patent and are working to further improve the process. They are also looking into other applications for the upncycling method.

1. What’s the main purpose of the researchers work?

A．To expand the use of 3D printing	B．To make better use of plastic waste.
C．To call on people not to throw away plastic.	D．To show off their high-technology methods.

2. What does the underlined phrase “this stuff” in paragraph 2 refer to?

A．The high-quality resin.	B．Polylactic acid.
C．The upcycling method.	D．Plastic food packing

3. Why does the author mention “a Lego castle” in the last but one paragraph?

A．To illustrate the process of remodeling	B．To explain how to deal with Lego bricks
C．To show the difficulties of their research.	D．To offer a model for the better improvement

4. What might be the best title of the text?

A．The Inexpensive Chemical Used to Break Down the PLA

B．Newly-developed 3D Printer for More Plastic Applications

C．New Way Found to Turn Plastic Waste Into Valuable Products

D．The Upcoming Age of New Plastic Without Pollution to the Environment

【推荐2】Artificial intelligence (AI) could help stop one of the biggest dangers to the Great Barrier Reef(大堡礁), amazingly saving huge areas of coral(珊瑚) from a harmful starfish. Google has teamed with scientists from the CSIRO to create AI software(软件) that could pick out the dangerous starfish, which is one of the natural wonder’s three biggest killers.

The new way, using footage from an underwater camera to recognize starfish outbreaks on the Queensland reef, takes the place of an old method and early results show as well as cutting down man’s work, the new software has the advantage of correctly picking out more of the dangerous life on coral, stopping damaging outbreaks before they occur.

Professor Russ Babcock, an expert with CSIRO, said Google’s AI technology, developed over 18 months, could be trained to find out starfish more easily than the old method developed in the 1970s. “We used to send out divers to count the starfish one by one. Now we just look at the images collected and the program can find 20 at a time,” he said.

Google CEO Sundar Pichai said he was excited about the company’s effort put into the reef project. “We have put a lot of effort into the engineering in Australia and we will continue to do more work around AI there,” he said. “There are other good ideas about the technology and you will see us build on it. Our goal with our AI research teams is to strike partnerships with other groups, like universities and governments, to give its full play.”

Professor Babcock said the AI software, which would be put into use on other reefs worldwide, was not the only solution to the starfish affecting the Great Barrier Reef, but one that could have an wide application.

1. What is the function of Google developing the AI software?

A．To test a new camera.	B．To kill dangerous fishes.
C．To protect the environment.	D．To pick out a kind of starfish.

2. What advantage does the AI technology have over the old method?

A．It is less likely to break down.	B．It can be started more quickly.
C．It costs less for its development.	D．It can do the work more easily.

3. What’s Sundar Pichai’s attitude towards the reef project?

A．Doubtful.

B．Uncaring.

C．Disapproving.

D．Supportive.

4. Which of the following can be the best title for the text?

A．A Harmful Starfish Affects Coral

B．A New Software Helps Save the Reef

C．What Makes AI Work Better?

D．Why Is the Reef in Danger?

【推荐3】To solve a big environmental problem, chemists have been thinking small. Really small: a new mini robot with the purpose of helping clean up tiny plastic polluting water across the globe.

The new microrobots, each of which is no bigger than the tip of a pencil, are magnetic (磁性的) and shaped like four-pointed stars. When the sunlight shines on them, they can swim in a specific direction; when the sunlight disappears, they stop moving. Finding a piece of plastic, they hold onto it, produce chemical reactions and start to break it down.

The project is led by chemist Martin Pumera, a researcher who also studies ways to build microrobots at the Czech University in Prague. About ten years ago, he noticed the microplastic was everywhere, from the bottom of the ocean to the ice on the top of mountains. It even turned up in drinking water, both bottled and tap water. Just think about how much plastic you encounter every day. It doesn’t easily degrade (降解), which is a big problem. Therefore, Pumera chose to focus on the problem of water pollution caused by microplastic.

The researchers tested the microrobots on four types of plastic in the lab. After a week, all four began degrading, losing between 0. 5 and 3 percent of their weight, which indicated they were breaking down. The robots also turned the plastic’s smooth surface into rough. Finally, they could be collected for reuse along with the plastic waste without causing new pollution.

In fact, Pumera says they still have a long way to go. These microrobots are unlikely to succeed in degrading all types of plastics. They’ll also need a lot of testing to show that they’re safe in open waterways, such as at sea. But he thinks that these challenges can be overcome. Someday, the microrobots will play a big role in a worldwide cleanup effort.

1. What can be learned about the new microrobot?

A．It is of a round shape.	B．It is as small as a pencil.
C．It is driven by sunlight.	D．It uses physical reaction.

2. What inspired Pumera to design the microrobot?

A．The ice on the mountains.	B．Secrets of the ocean bottom.
C．The lack of drinking water.	D．The microplastic pollution.

3. How does a microrobot deal with the plastic?

A．Collecting it for reuse.	B．Making its surface smooth.
C．Absorbing it completely.	D．Breaking it down to some extent.

4. What is Pumera’s attitude to their future research?

A．Doubtful.	B．Confident.
C．Regretful.	D．Critical.

【推荐2】Scientists have solved a puzzle about modern humans, after research showed that a famous skull of a human ancestor found in South Africa is a million years older than experts thought. This discovery has changed what we know of human history.

The skull, which scientists have named “Mrs Ples”, is from an ape-like human relative from a species called Australopithecus africanus (南方古猿). It was found near Johannesburg in 1947 and, based on evidence from its surroundings, was thought to be between 2. 1 and 2. 6 million years old. This puzzled scientists, because although Mrs Ples looks like a possible early ancestor of early humans, the first true humans had already evolved by the time she apparently lived. For this reason, scientists had decided that Australopithecus afarensis, a similar species from East Africa that lived about 3.5 million years ago, was our most likely ancestor instead.

To get a more accurate age for Mrs Ples, a team led by Professor Darryl Granger of Purdue University in Indiana, US, used a new method to date the sandy rocks where the skull lay. They measured the amount of certain chemicals in rocks, which form at a steady rate when they are exposed to cosmic rays (宇宙射线) on Earth’s surface. Once rocks are buried, these chemicals stop forming and slowly disappear;the surviving amount reveals how much time has passed since the rock (or bones) were on the surface.

The new study shows that Mrs Ples and other australopithecine bones nearby are between 3.4 and 3.7 million years old. This means they lived at the same time as their East African relatives, so that either group could have given rise to modern humans. However, team member Dr Laurent Bruxelles pointed out that over millions of years, at only 2,500 miles away, these groups had plenty of time to travel and to breed with each other. In other words, the groups could quite easily have met, had children together and both been part of the history of modern humans.

1. What can we learn about Mrs Ples from the first two paragraphs?

A．It is a skull found in East Africa.

B．It is the most possible ancestor of humans.

C．It is a million years older than scientists expected.

D．It is proved to live between 2.1 and 2.6 million years ago.

2. How did scientists get the accurate age of “Mrs Ples”?

A．By studying the effect of cosmic rays.

B．By calculating the forming rate of chemicals.

C．By locating the sandy rocks where the skull lay.

D．By measuring the surviving amount of chemicals.

3. What can we infer from the new study?

A．Modern humans came into being in East Africa.

B．Mrs Ples travelled and had children with East African relatives.

C．The history of modern humans might begin 3.5 million years ago.

D．Ape-like species from Africa could have interacted with each other.

4. Which of the following can be the best title of the passage?

A．Historical Puzzle Unsolved	B．Ancestor Mystery Solved
C．Mrs Ples: The Earliest Human Being	D．Mrs Ples: A Famous Skull

【推荐3】Humans and horses have enjoyed strong working relationships for nearly 10,000 years. Can these age-old relationships teach us something about building robots? Researchers at the University of Florida carried out research and said yes. “As we work to improve how humans communicate with robots, I thought why not learn from our partnership with horses to help solve the problem of natural interaction (互动) between humans and robots?” said Eakta Jain, an associate professor of computer and information science and engineering.

Looking at our history with animals to help shape our future with robots is nothing new. But Jain and her colleagues are the first to bring together engineering and robot researchers and horse experts and trainers to do on-the ground field studies with the animals.

Jain first reached out to Joel McQuagge, who managed the UF Horse Teaching Unit. He provided Jain with full access, so Jain spent months observing classes. She interviewed and observed horse experts, including horse trainers and owners. Jain’s notes resulted in findings and design ideas that can be applied by robot designers.

“Some of the findings are easy to visualize (可视化), while others are not very specific,” Jain said. “For example, we learned that a horse speaks with its body. You can see its ears pointing to where something caught its attention. We could build similar types of expressions without speech in our robots, like ears that point to something visual in the car when there’s a person walking on that side of the street.”

A groundbreaking finding is the sense of respect. When a trainer works with a horse, he looks for signs of respect from the horse for its human partner. “We don’t typically think about respect in the situation of human-robot interaction,” Jain says. “Can we design behaviors similar to what the horse uses? Will that make the human more willing to work with the robot?”

1. Why does the author mention horses in the first paragraph?

A．To provide examples.	B．To make comparisons.
C．To introduce the topic.	D．To support his argument.

2. How did Jain carry out her research?

A．She interviewed engineers and robot designers.

B．She worked with horse experts for observations.

C．She discussed her design with robotics and horse experts.

D．She checked historical records of human-horse partnerships.

3. What lesson can robot designers draw from Jain’s notes?

A．Body language can be designed into robots.

B．Early warnings could be given if something happens.

C．Robots may hardly understand non-speech instructions.

D．Robots can perform better than horses in locating things.

4. What can be the best title for the text?

A．Study the Influences of Robots on Horse Training

B．Improve the Interaction Between Robots and Humans

C．Explore the Relationships Between Humans and Horses

D．Build Better Robots Through the Experience with Horses