3 . As the effects of climate change become more disastrous, well-known research institutions and government agencies are focusing new money and attention on an idea: artificially cooling the planet, in the hopes of buying humanity more time to cut greenhouse gas emissions.

That strategy, called solar climate intervention (干预) or solar geoengineering, involves reflecting more of the sun’s energy back into space — abruptly reducing global temperatures in a way that imitates the effects of ash clouds flowing out from the volcanic eruptions. The idea has been considered as a dangerous and fancied solution, one that would encourage people to keep burning fossil fuels while exposing the planet to unexpected and potentially threatening side effects, producing more destructive hurricanes, wildfires floods and other disasters.

But. as global warming continues, producing more destructive hurricanes, wildfires floods and other disasters, some researchers and policy experts say that concerns about geoengineering should be outweighed by the imperative to better understand it, in case the consequence of climate change become so terrible that the world can’t wait for better solutions.

One way to cool the earth is by injecting aerosols (气溶胶) into the upper layer of the atmosphere. where those particles reflect sunlight away from the earth. That process works, according to Douglas MacMartin, a researcher at Cornell University.

“We know with 100% certainty that we can cool the planet,” he said in an interview. What’s still unclear, he added, is what happens next. Temperature, MacMartin said, is an indicator for a lot of climate effects. “What does it do to the strength of hurricanes?” he asked, “What does it do to agriculture production? What does it do to the risk of forest fires?”

Another institution funded by the National Science Foundation will analyze hundreds of simulations of aerosol injection, testing the effects on weather extremes around the world. One goal of the research is to look for a sweet spot: the amount of artificial cooling that can reduce extreme weather events without causing broader changes in regional rainfall patterns or similar impacts.

1. Why do researchers and government agencies work on cooling the earth?

A．To prevent natural disasters.	B．To win more time to reduce gas emissions.
C．To imitate volcanic eruptions.	D．To encourage more people to bur fossil fuels.

2. What are researchers worried about in terms of global warming?

A．More volcanoes will throw out.

B．More solar energy will go into space.

C．More disasters will endanger the future of the world.

D．People will keep burning fossil fuels to keep warm.

3. What can be inferred from Douglas’ words in an interview?

A．He thinks more research remains to be done.

B．He is optimistic about the effect of cooling the earth.

C．He is concerned about the reduction in agriculture production.

D．He disapproves of the practice of solar climate intervention.

4. What does the underlined words “sweet spot” in the last paragraph mean?

A．The rainfall pattern of a region.

B．The modest drop in temperature.

C．The number of extreme weather events.

D．The injection amount of aerosol.

4 . As heat waves continue to ravage the planet, air conditioners are becoming more and more common. However, these "active" cooling devices are posing problems because the electricity consumption which most people are concerned about and the release of ozone-damaging chemicals worsen the greenhouse gas effect, resulting in the creation of heat islands and further thermal pollution. Therefore, "passive" cooling, which doesn't have such effects, has attracted considerable attention from both scientists and ordinary people in recent years.

In a recent study, a team of researchers from China and US presented an eco-friendly, low-cost smart coating to keep buildings cooler while consuming zero electricity. Infrared radiation-based passive cooling has been investigated since 2014, but challenges, mainly the expensive and unsustainable design, have greatly limited their large-scale and widespread application. Besides, the imbalance in cooling ability of these coatings during the day and night tends to lead to great day-night temperature differences as more heat is lost than gained at night.

The solution therefore requires a "smart" mechanism that can both enhance daytime cooling and minimize nighttime heat loss. To do this, the researchers created a new smart coating comprised of conventional building materials, including titanium dioxide nanoparticles, fluorescent microparticles, and glass microspheres that were engineered to reflect most of the sunlight. Specifically, the titanium dioxide particles effectively reflect sunlight through light scattering（撒播）while the fluorescent particles increase the amount of reflection by changing the absorbed sunlight into fluorescence emissions, which drive more heat away from the building. Meanwhile, the glass microspheres re-send mid-infrared broadband radiation, allowing not only heat loss, but allowing heat exchange to take place between the building and the sky.

The coating was tested on a model concrete building. Through this efficient heat exchange with the sky, daytime cooling was strengthened while nighttime cooling was reduced. The building's inside temperature was always maintained at around 26℃, even when the out-side temperature varied from 24℃ to 37℃ during the day. We believe this new coating will make it to commercialization soon, enabling a sustainable, passive cooling technology that could help to fight climate change and the global energy crisis.

1. What is the virtue of passive cooling?

A．It is simple to design.	B．It uses no chemicals.
C．It is smart.	D．It uses no power.

2. Why couldn't the former coating be applied commercially?

A．It was hard to design.

B．Its material was hard to produce.

C．Its heat loss and cooling are imbalanced.

D．It wasn't tested on a model concrete building.

3. Which of the following can replace the underlined word "mechanism" in paragraph 3?

A．Metal.

B．System.

C．Platform.

D．Building.

4. What is the text mainly about?

A．The principle of air-conditioning.

B．The differences between active and passive cooling.

C．A new coating to keep buildings cool without electricity.

D．A new building to maintain its inside temperature without electricity.

5 . We recognize our friends’ faces. And we’re not alone. Many social animals can identify individuals of their own species by features of their faces. That's important, because they need to be able to change their behavior depending on who they meet. And a recent research has shown that some species of monkeys, birds, and domesticated (家养的) animals can even tell different faces apart by looking at photographs alone.

Ethologist Léa Lansade of the French National Research Institute for Agriculture, Food and Environment did an experiment to find out how well horses can recognize individual people in photographs.

She and her team first taught the horses how to “choose” between two side-by-side pictures by touching their noses to a computer screen. The horses were then shown photos of their present keeper alongside faces of unfamiliar humans. They had never seen photos of any of the people before. The horses correctly identified their current keeper and ignored (忽视) the stranger’s face about 75%of the time. In fact, even though the horses didn't get it right every single time, they were at least as correct in picking out their earlier keeper as they were at identifying their present one.

The results suggest that not only can horses differentiate between familiar and unfamiliar human faces, they also naturally understand that photographs are two dimensional representations (二维呈现) of real life, without any other intimations such as smell or sound. And they’re even better at this than our oldest animal parter, the domestic dog.

In addition, horses seem to have a strong long-term memory for human faces, like their long lifespan and history of domestication. In future experiments, the researchers would like to test whether looking at photos of people that they have had bad experiences with in the past might cause horses to act anxious or even avoidance. So maybe think twice before doing anything that might give a horse a long face.

1. Why did researchers show the horses both the keeper’s photos and the strangers’?

A．To find out what horses would do in the experiment.

B．To see why horses could recognize the keeper in the pictures.

C．To test whether horses could recognize the strangers in pictures.

D．To study to what degree horses can make out different people in pictures.

2. What does the underlined word “intimations” in paragraph 4 refer to?

A．Clues.	B．Differences.
C．Photographs.	D．Senses.

3. What are researchers still uncertain about?

A．Whether horses can live longer than other animals.

B．Whether horses can remember human's faces for a long time.

C．Whether horses can show their emotions at the sight of photos.

D．Whether horses are better at recognizing photos than other animals.

4. What is the purpose of the text?

A．To talk about animals’ species.

B．To explain animals’ facial features.

C．To show animals’ behaviour for adaptation.

D．To introduce animals’ ability to identifying faces.

6 . The concept of ownership comes so easily to humans that even preschoolers have got it. Robots, on the other hand, often struggle to grasp such abstract concepts. Now a well-mannered robot that can make it has been programmed.

“Teaching robots ownership-related etiquette (礼仪) is really, really worthwhile,” says Matthias Scheutz, a computer scientist at Tufts University. "We can't just send out robots who are unaware of who owns what... If I instruct a robot to ‘build a fence’, and it goes to the neighbor’s and starts ‘stealing’ boards, that's not what we have in mind.”

The new socially conscious robot can learn who owns what from clear statements as well as its own observations. The robot learns its code of conduct (行为准则) from direct orders and generalizing from specific examples. For instance, if the robot is told not to touch several objects that it knows belong to specific people, the robot will deduce that, as a general rule, it shouldn’t touch owned objects.

Artificial intelligence (AI) expert Xuan Tan and colleagues at Yale found out how the robot reacts in experiments with blocks on a table. In one session, Tan played with only the red blocks, leading the robot to infer that these blocks belonged to the same person. When Tan instructed the robot to throw away everything on the table and the machine reached for a red block, Tan stopped the robot, saying, “That's mine.” Now aware that it should not throw Tan’s belongings, and assuming that the rest of the red blocks belonged to Tan as well, the robot cleared the table of everything but red blocks.

Later, when Tan's colleague Jake Brawer directed the robot to throw out a red block, the robot replied, "Sorry, I'm forbidden to throw it away if it's owned by Tan.” Though robots may have more difficulty understanding who owns what in situations filled with far more objects of much wider variety than blocks on a table. Scheutz called it a good "first attempt” at equipping robots with an appreciation of ownership.

1. What does the second paragraph focus on?

A．The way of teaching robots ownership.	B．The basics of the human-robot relationship.
C．The benefit of robots learning ownership.	D．The importance of robots learning code of conduct.

2. Which is closest in meaning to the underlined word "deduce” in paragraph 3?

A．Conclude.

B．Admit.

C．Agree.

D．Doubt.

3. Why did Xuan Tan use the blocks in experiments?

A．To train the robot.	B．To predict the robot’s move.
C．To test the robot's behavior.	D．To study the preference.

4. What does the author want to show by mentioning Jake Brawer in the last paragraph?

A．The robot knows how to obey.	B．The robot can learn who owns what.
C．The robot follows no wrong orders.	D．The robot can solve complex situations.

7 . A review of 100 years of fossil evidence reveals that 100 million years ago part of the Sahara Desert was arguably the riskiest place on our planet,wih a concentration of large predatory(食肉的）dinosaurs unmatched in any comparable modern ecosystem on land. The analysis of fossils from theso-called Kem Kem beds shows the presence in the area of large-scale predatory dinosaurs,reptiles and other hunters, all living together in what was at the time a river system full of very large fish, rather than a desert.

Paleontologist Nizar Ibrahim, lead author of the study, said that the Kem Kem ecosystem was a highly enigmatic place,ecologically speaking, since typically ecosystems present a larger number of plant-eating animals than predators, and predators themselves will come in a variety of sizes,with one larger predator being dominant. In the Kem Kem beds,fossils of predators outnumber those of plant-eating dinosaurs, and several of the predators living together in the area, such as the Carcharodontosaurus, the Spinosaurus,the Abelisaur and the Deltadromeus, were as big as a Tyrannosaurus rex (T.rex) - one of the largest dinosaurs that ever lived. This is strange “even by dinosaur standards,” according to Ibrahim, since the T. rex, which was present in North America tens of millions of years later, was “the unarguable ruler of its ancient ecosystem.”

It is unlikely that the large predators in the Kem Kem ecosystem ate one another. What's more realistic, according to Ibrahim, is that they ate the abundant and supersized fish present in the area - fish like coelacanths"the size of a car” and sawfish that could reach 25 feet in length.

The study of the Kem Kem beds carried out by Ibrahim and a group of international researchers across the U.S., Europe and Africa draws attention to the importance of learning more about Africa,which remains paleontology's forgotten continent.It shows that African ecosystems"do not simply copy the ones we know from North America,Europe or other better-known places,"and it also reveals clues about what happens to life when dramatic changes in climate come into play.

1. What does the underlined word “enigmatic" in Paragraph 2 probably mean?

A．Dangerous.

B．Peaceful.

C．Puzzling.

D．Remote.

2. What can be learned about the Kem Kem ecosystem?

A．The T.rex was the real ruler of the ecosystem.

B．There once lived dangerous supersized dinosaurs.

C．There was an underground river instead of a desert.

D．The number of plant-eating dinosaurs went beyond that of predators.

3. Which of the following would Ibrahim agree with?

A．Sawfish once completely dominated North America.

B．Coelacanths were much larger than the Deltadromeus.

C．The Carcharodontosaurus and the Spinosaurus lived on fish.

D．The Abelisaur and the T. rex became extinct at the same time.

4. What does the study of the Kem Kem beds reveal?

A．African ecosystems have their uniqueness.

B．Humans have caused great changes in climate.

C．Fossils of predators proved to be alien species.

D．The Sahara Desert was formed 100 million years ago.

8 . “Do not tell anyone”. We often hear these words when someone tells us a secret. But keeping a secret is hard. We’re often tempted（引诱）to “spill the beans”, even if we regret it later.

According to the professor, Asim Shah, keeping a secret may well “become a burden”. This is because people often have an “eager and anxious urge（冲动）to share it with someone”. An earlier study, led by Anita, a scientist at the University of Notre Dame, US, suggested that keeping a secret could cause stress. People entrusted（托付）with secrets can suffer from depression, anxiety, and body aches, reported the Daily Mail.

Secrets are so often getting out. Why do people share them at all? Shah explained that people often feel that it will help them keep a person as a friend. Another reason people share secrets is guilt over keeping it from someone close to them. A sense of distrust can develop when people who are close do not share it with each other. “Keeping or sharing secrets often puts people in a position of either gaining or losing the trust of someone, ”according to Shah.

He added that talkative people could let secrets slip out. But this doesn’t mean that it is a good idea only to share secrets with quiet people. A quiet person may be someone who keeps everything inside. To tell such a person a secret may cause them stress, and make them talk about the secret.

Shah said that to judge whether to tell someone a secret, you’d better put yourself in their position, Think about how you would feel to be told that you mustn’t give the information away. Shah also recommended that if you accidentally give up someone’s secret you should come clean about it. Let the person know that their secret isn’t so secret anymore.

1. Why does the author say keeping a secret may “become a burden”?

A．Because people are born not to be able to keep secrets.

B．Because when people have secrets, their bodies ache.

C．Because keeping secrets is certain to cause depression.

D．Because keeping secrets could probably be harmful to health.

2. How many reasons have been mentioned in Paragraph 3 why people tend to share secrets?

A．2.

B．3.

C．4.

D．5.

3. What does the underlined words “spill the beans” mean?

A．To fall by accident.	B．To let out secrets on purpose.
C．To spread secrets to everyone around.	D．To give away secrets unintentionally.

4. What can we learn from the passage?

A．Quiet people are more likely to keep the secrets to themselves.

B．Sharing secrets helps establish friendship or get over the, sense of guilt.

C．Putting yourself in others’ shoes helps realize the importance of keeping secrets.

D．A person who is asked to keep a secret will suffer from psychological problems only.

9 . Dry Ice is a unique substance which has many uses. Essentially, dry ice is frozen CO2. The first report of what we now call dry ice came from the French chemist Charles Thilorier in 1834. In 1924, the Drylee Corporation of America named the solid form of CO2 as "Dry Ice", which is what it is popularly called today.

At normal atmospheric pressure, CO2changes directly from solid to gas. It skips the liquid phase（阶段）which makes regular ice wet. Frozen CO2is also much colder than regular ice. But regular ice freezes at 32 degrees Fahrenheit, CO2 changes from gas to solid at -109.3 degrees Fahrenheit. This extremely cold temperature makes it very dangerous to handle with bare hands. It can cause frostbite in a very short period of time.

Dry ice has been used for a variety of purposes throughout the past century. Its primary use is to refrigerate food when electrical refrigeration isn't available. Through the process of sublimation (when CO2 changes from solid to gas), it can maintain cold food for a long time.

If you've ever been to a play and seen heavy fog on the ground, it is likely that you have seen dry ice in action. This effect can be achieved because CO2 is heavier than air, so evaporated （挥发的）CO2 will sink and accumulate on the ground.

Another interesting use for this substance is to bait（诱杀）insects like mosquitoes. These insects have sensors which guide them to CO2. They find the high concentration of CO2 in dry ice quite attractive.

Mars has long been a mystery for human beings. We have been looking for evidence of life on Mars. In the 1960s scientists guessed that the polar ice cap of Mars was made of frozen CO2. More recent observations have shown that while the topmost layer consists of frozen CO2, the most of it is probably regular frozen water.

1. Frozen CO₂ gets its name of "Dry Ice" mainly because______.

A．it is very easy to make it dry

B．we can't melt it and it doesn't get wet

C．it looks like ice at a low temperature

D．it is solid like ice at -109.3 degrees Fahrenheit

2. The underlined word "frostbite" in the second paragraph probably means_______.

A．the shakes caused by cold

B．damage caused by freezing

C．a fever caused by being cold

D．a sharp pain caused by bums

3. According to the passage, dry ice can be used to_______.

A．freeze most of food in the next century

B．increase the production of farming

C．make a vivid fog effect on stages

D．help to improve the environment

4. What does the last paragraph mainly tell us?

A．Dry ice on Mars is near the polar.

B．Not much dry ice has been found on Mars.

C．The polar ice cap of Mars is unique.

D．No frozen CO, on Mars can be melt.

10 . Described as the world’s most environmentally friendly protein（蛋白质）, Solein is made by applying electricity to water to release bubbles of carbon dioxide and hydrogen. Living microbes (微生物) are then added to the liquid to feed on the carbon dioxide and hydrogen bubbles and produce the Solein, which is then dried to make the powder. It’s a chemical change process similar to beer brewing. The dried Solein has a protein content of 50 percent and looks and tastes just like wheat flour.

“It is a completely new kind of food, a new kind of protein, different to all the food on the market today in how it is produced as it does not need agriculture.” Dr Pasi Vainikka, the chief manager of Solar Foods told The Guardian. The process used to produce Solein—changing hydrogen and carbon dioxide is amazing, as the wonder food can be produced anywhere in the world. It’s also 10 time-efficient than photosynthesis (光合作用), and 10 to 100 times more environment and climate-friendly in water use than animal or plant-based food production.

“Solein also contains all the essential amino acid (氨基酸),but because it is produced using carbon and electricity, it does not require large amounts of land to produce, ” the Solar Foods website explains. “Another unique characteristic of Solein is that it is able to take carbon directly from carbon dioxide without needing a source of sugar.”

While Solar Foods does not expect Solein to challenge conventional protein production methods in the next two decades, it does expect it to become a “new harvest” for humanity, which is significant considering so far we have only relied on plants and animals for sustenance. The Helsinki-based company plans to open its first Solein factory at the end of 2021 and increase production to two billion meals per year by 2022.

1. Why is Solein described as environmentally friendly?

A．Because it is man-made by using electricity.

B．Because it contains all the nutrition people need.

C．Because it is made consuming less land and energy.

D．Because it is produced from water and carbon dioxide.

2. What does Solar Foods expect of Solein?

A．It’ll have a rewarding future.

B．It’ll reach consumers in 2020.

C．It’ll challenge traditional protein production.

D．It’ll be a complete replacement for plants and animals.

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

A．survival	B．food
C．material	D．support

4. Where is this text most likely from?

A．A textbook.	B．A novel.
C．A magazine.	D．A brochure.