Global food demand will double by 2050, according to a new projection, and the farming techniques used to meet that unprecedented(空前的) demand will significantly determine how severe the impact is on the environment, researchers said.
The study researchers warned that meeting the demand for food would clear more land, increase nitrogen(氮) use and significantly add to carbon dioxide and other greenhouse gas emissions.
“Agriculture’s greenhouse gas emissions could double by 2050 if current trends in global food production continue,” study researcher David Tilman, of the University of Minnesota, said in a statement. “This would be a major problem, since global agriculture already accounts for a third of all greenhouse gas emissions.”
The researchers studied various ways in which the increasing food demand could be mentioned. They found that the most environmentally friendly and cost-effective approach would be for more food producers to adopt the nitrogen-efficient “intensive” farming method, which involves the heavy use of labor and the production of more crops per acre.
This approach was shown to be more effective than the “extensive” farming currently practiced by many poor nations, a method that includes clearing more new land to produce more food.
Different farming methods produce significantly different yields, the researchers found — in 2005, the crop yields for the wealthiest nations were more than 300 percent higher than what the poorest nations produced.
According to their analysis of the effects of extensive farming, if poorer nations continue using this method, by 2050 they will have cleared an area larger than the United States, about 2.5 billion acres. However, if wealthy nations help poorer nations to improve food yields by incorporating(吸收) intensive farming practices, that number could be reduced to half a billion acres.
The researchers stress that the environmental effects of meeting future food demand depend on how global agriculture expands and develops.
“Our analyses show that we can save most of the Earth’s remaining ecosystems by helping the poorer nations of the world feed themselves,” Tilman said.
1. What is the best title of this passage?| A．The World Will Need Double Food by 2050 |
| B．Man Will Face the Risk of Lacking Food in the Future |
| C．Future Farmers Hold Environment’s Fate in Their Hands |
| D．Different Farming Methods Produce Significantly Different Yields |
| A．very cost-effective |
| B．to produce more crops per acre |
| C．at cost of more new land to produce more food |
| D．very environmentally friendly |
| A．poorer nations mainly use the intensive farming |
| B．wealthy nations mainly use the extensive farming |
| C．the intensive farming needs less food producers |
| D．the extensive farming has a worse effect on ecosystems |
| A．poorer nations |
| B．the effects of extensive farming |
| C．wealthy nations |
| D．future food demand |
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【推荐1】Now, chemists have discovered new potential in abundant building blocks: Through a series of reactions, scientists have shown that conventional bricks can be transformed into energy storage devices powerful enough to turn on LED lights. “What we have demonstrated in our paper is sufficient enough for you to light up emergency lighting that's in a hallway or sensors that could be put inside the walls of a house, "said Julio M. D’ Arcy, an assistant professor of chemistry at Washington University in St. Louis, Missouri, and one of the study's authors. "The next step is trying to store more energy, so that you can power bigger devices--like maybe a laptop--directly from the walls of the house. ”
“Bricks have been prized by architects for their capacity to store heat, but using them to hold electricity has never been tried before, "D'Arcy said. To allow the bricks to store electricity, the researchers pumped a series of gases inside the brick. "The gases react with the brick's chemical components, coating them with a web of plastic nanofiber (纳米纤维）known as a PEDOT, which is a good conductor of electricity, "he said. Though PEDOT can store large amounts of energy, this supercapacitor (超级电容器）cannot hold onto that charge or deliver sustained energy over long periods of time like batteries can. “A battery will give you energy density that will allow you to drive 300 miles, but a supercapacitor will allow you to accelerate very quickly at a red light,” D’ Arcy said.
Still, scientists see potential in the bricks as a possible green energy solution. Right now, these "smart bricks" cannot compete with the energy storage potential of the lithium-ion (锂离子）batteries used in many solar power systems. However, there is hope that this new technology could be developed to provide a new storage method using readily available materials.
“The performance is a long way short of custom-made supercapacitors, but the principle is proven and there is significant room for improving the storage characteristics by optimizing the structure and chemistry of the bricks,” said Dan Brett, a professor of electrochemical engineering at University College London, who was not involved in the study.
1. What will the scientists do about the bricks next according to M. D'Arcy?| A．Put the bricks into commercial use. |
| B．Refer their paper to academic journals. |
| C．Expand the bricks' ability of storing power. |
| D．Develop new smart laptop with powered bricks. |
| A．It allows bricks to take up less space. |
| B．It can protect bricks with a powered coat. |
| C．It helps bricks store and conduct electricity. |
| D．It can make the powered vehicles travel farther. |
| A．They need much more development. |
| B．They are more environmentally-friendly. |
| C．They will be released into the market soon. |
| D．They can be made according to consumers' requirements. |
| A．Making the most of. | B．Trying out for. |
| C．Breaking up with. | D．Breaking away from. |
【推荐2】As every mobile-phone owner knows, after a year or so the battery starts to fade and the beast needs recharging more frequently. That is a nuisance, but a phone’s batteries can be replaced fairly cheaply or the whole handset traded in for the latest model. An electric car, however, is a much bigger investment. Batteries are its priciest component, representing around 30% of an average of mid-size vehicle. Apart from increasing the risk of running out of juice and leaving a driver stranded, a deteriorating battery quickly destroys a car’s second-hand value.
To provide buyers with some peace of mind, car makers guarantee their batteries, typically for eight years or around 200,000 km. Producers are now, though, planning to go much further than that, with the launch of “million-mile” (1.6km-kilometre) batteries. Elon Musk has hinted that Tesla has a million-mile battery in the works. And over in Detroit, General Motors (GM) is in the final stages of developing an advanced battery which it says has similar longevity.
“It’s a great catchphrase; the million-mile battery,” says George Crabtree, director of the Joint Centre for Energy Storage Research at Argonne National Laboratory, near Chicago. “But the fact that you can drive a million miles may not be the most relevant parameter to look at.” Regular fast-charging reduces battery life, as do overcharging and deep discharging. Driving in extremely hot or cold weather doesn’t help either. And battery life will diminish even if you just leave the car in the garage. The real point of a million-mile battery is that the technological advances required to make it possible will deal with these things as well.
The lithium-ion (Li-ion) batteries which power electric cars age in two ways: with time and with use. Battery-makers-call time-dependent ageing “calendar ageing”. It is consequence of the gradual degradation of some of the materials employed in battery construction, which reduces a battery’s ability to hold a charge. Leaving a car with a fully rather than partly charged battery, for example, can increase the rate of calendar ageing. Use-dependent ageing is a consequence of the number of discharge-recharge cycles a battery goes through. It is caused by the complex chemical reactions that take place when a battery is operating. Some of these are essential to a battery’s job of storing and releasing energy.
Battery technology is improving all the time. As a consequence, so are calendar and use-dependent lifetimes. Getting direct experience of how electric cars are used is helping researchers come up with ways to mitigate (缓和) some of the side reactions, says Tim Grewe, the head of GM’s electrification strategy. The company employs remote “telematics” monitoring to keep track of how batteries are performing in its cars, and also takes back some batteries from high-mileage drivers and those living in extreme environments, such as deserts and mountainous regions, for analysis.
Dealing with impurities that get into batteries helps to extend their lives. Water, for example, reacts with salts in the electrolyte to form an acid, which attacks the electrodes. To prevent this, GM has developed an addictive made from a type of material called a zeolite. Zeolites are molecular sponges. GM’s version serves to mop up any moisture which enters a battery cell.
Adding a little aluminium to a nickelcobalt-manganese cathode, a type that is widely used in Li-ion batteries, save on cobalt, the most expensive ingredient in a battery. But the aluminium delivers other benefits as well. It boosts the battery's energy density, meaning a car can travel farther on a single charge. It also make the battery last longer.
As a marketing device, the million-mile battery will give electric-car buyers more confidence that their batteries are robust. And by no means are million-mile batteries the limit of engineers’ aspirations. The next objective is to replace Li-ions’ liquid electrolytes with solid ones. That would keep the ions under stricter control and allow even longer driving ranges. This could make a two million-mile battery a feasible objective. If that day comes, the tables would have been turned. From being the first part of a car to fail, its battery will have come the last.
1. What does the underlined sentence in the first paragraph mean?| A．It is more profitable to invest in an electric car than in a mobile phone. |
| B．Spending more money on an electric car can increase its second hand value. |
| C．It’s much more costly to replace the failed batteries of an electric car with new ones. |
| D．Compared with electric cars, batteries are of less importance to mobile phones. |
| A．Unplugging an electric car once it’s fully charged. |
| B．Often charging the car in “fast” mode to save time. |
| C．Driving an electric car on sweltering summer days. |
| D．Leaving the car in the parking lot for a long time. |
| A．Monitoring and studying batteries’ performance in long-distance traveling. |
| B．Adding zeolite to encourage the acidifying chemical reaction in the battery. |
| C．Using aluminium to improve the battery’s performance enabling the car to travel farther. |
| D．Keeping the battery partly charged to reduce its rate of “calendar ageing”. |
| A．The current technology enables an electric car to drive a million miles on a single charge |
| B．Electric car engineers are always on the go to develop batteries with greater longevity |
| C．Policies on the choice of battery materials will be tightened to control the traveling range |
| D．Drivers of future electric cars will no longer be worried about battery failure |
【推荐3】What if your smartphone or laptop starts charging as soon as you walk in the door? Scientists have developed a specially-built room that can conduct energy to a variety of electronic devices within it without plugs or batteries.
It’s a custom test room of about 18 cubic meters, built from conductive aluminum(铝) panels with a metal pole running down the middle. When the scientists ran an electric current through the walls and pole following a set pattern, it generated two separate magnetic (磁的) fields: one that fills the center of the room and the other that covers the corners, thus allowing any devices within the space to charge.
By carrying out tests, scientists found their method could deliver 50 watts of power throughout the room. firing up all devices they tested. Without safeguards, running currents through the room's metal walls would typically fill it with two types of waves: electric and magnetic. This presents a problem, because electric fields can produce heat in biological tissues and pose a danger to humans. So the team built capacitors, devices that store electric energy, in the walls. “It limits the safe magnetic fields to the room volume while limiting risky parts to all the components built in the walls.” lead author Takuya Sasatani explains.
The scientists also tested the room’s safety, and the result showed the absorption of energy would remain well below acceptable limits. “We’re not saying this technology is safe under all circumstances—we’re still exploring,” says study co-author Alanson Sample. “But it shows us that there's still much area to explore.”
But applying the technology is still far in the future. It’s just too burdensome to put aluminum sheets all over the walls-that benefit doesn't make sense yet. “We’ve just developed a brand-new technique. Now we have to figure out how to make it practical,” Sample says. Meanwhile, scientists hope to improve the efficiency of power conduction and remove spots that the charge does not reach.
1. What does paragraph 2 mainly talk about?| A．What the room looks like. | B．How electric currents are generated. |
| C．How the special room works. | D．What the technology was developed for. |
| A．Produce electric power. | B．Measure magnetic field. |
| C．Stop devices from heating. | D．Protect people from harm. |
| A．Optimistic. | B．Cautious. | C．Doubtful. | D．Content. |
| A．The cost. | B．The safety. | C．The effectiveness. | D．The material. |
【推荐1】Heating and cooling equipment are the biggest users of energy in American homes. And homes are responsible for about one fourth of the nation’s total energy use. But there are surprisingly simple ways to deeply cut energy use，its effect on the environment and its cost. David Peabody and his team at Peabody Architects design passive homes. He says the design of a passive house aims to reduce energy demand to its lowest possible level. Passive houses use no solar，geothermal or wind energy equipment. But they are extremely energy efficient.
Mr Peabody says passive houses cut heating and cooling costs by about 90 percent. But what sets his design apart from other "green homes" is that it looks like any other home. Peabody Architects says it is building the first passive home in the Washington. D.C. area. But it will not he the last. In Arlington. Virginia. Roger Lin and his brother Eric are also building one. Roger Lin of Southern Exposure Homes explains that windows are sealed against leaks and have three layers of glass. The windows are airtight. On a cold winter day，the temperature inside the unfinished home is a comfortable 12 degrees，or 50 degrees Fahrenheit.
David Peabody says you can find passive honks all over the world. DAVID PEABODY：
"North Africa，for example，has a passive house community designing for very hot dry climates.” The first passive design was an apartment building in Darmstadt，Germany. Two physicists helped develop it about 20 years ago. Passive houses use some specialized materials. These include precast concrete panels and insulation(隔热).They also need to have special air treatment systems. Supporters say they cost only about five or eight percent more than traditional homes. But they use 10 percent of the energy for heating and cooling.
1. Which of the following is the advantage of passive houses?| A．They are extremely energy efficient. |
| B．They look much like the other houses. |
| C．They cost much less than traditional houses. |
| D．They are more comfortable than other houses. |
| A．Arlington | B．Mexico |
| C．North Africa | D．Germany |
| A．Passive homes are specially built for winter use. |
| B．Passive homes can be found everywhere in the world. |
| C．"Green homes" differ from traditional homes in their appearances. |
| D．The construction of passive homes takes advantage of high technology. |
| A．Objective. | B．Negative. |
| C．Doubtful. | D．Optimistic. |
【推荐2】The health of millions could be at risk because supplies of medicinal plants are being used up. These plants are used to make traditional medicine, including drugs to fight cancer. “The loss of medicinal plants is a quiet disaster,” says Sara Oldfield, secretary general of the NGO Botanic Gardens Conservation International.
Most people worldwide rely on herbal (药草制的) medicines which are got mostly from wild plants. But some 15,000 of the 50,000 medicinal species are under threat of dying out, according to report from the international conservation group Plantlife. Shortages have been reported in China, India, Kenya, Nepal, Tanzania and Uganda.
Over-harvesting does the most harm, though pollution and competition from invasive species (入侵物种) and habitat destruction all contribute. “Businessmen generally harvest medicinal plants, not caring about sustainability (可持续性),” the Plantlife report says, “damage is serious partly because they have no idea about it, but it is mainly because such collection is unorganized.” Medicinal trees at risk include the Himalayan yew (紫衫) and the African cherry, which are used to treat some cancers.
The solution, says the report’s author, Alan Hamilton, is to encourage local people to protect these plants. Ten projects studied by Plantlife in India, Pakistan, China, Nepal, Uganda and Kenya showed this method can succeed. In Uganda, the project has kept a sustainable supply of low-cost cancer treatments, and in China a public-run medicinal plant project has been created for the first time.”
“Improving health, earning an income and keeping cultural traditions are important in encouraging people to protect medicinal plants,” says Hamilton, “You have to pay attention to what people are interested in.”
Ghillean Prance, the former director of the Royal Botanic Gardens at Kew in London, agrees that medicinal plants are in need of protection. “Not nearly enough is being done,” he told New Scientist. “We are destroying the very plants that are of most use to us.”
1. From the first two paragraphs, we can learn that ________.| A．millions of people are threatened with-cancer |
| B．most countries see a shortage of herbal medicines |
| C．about two thirds of medicinal species will disappear |
| D．a number of medicinal species are in danger of extinction |
| A．pollution | B．habitat destruction |
| C．over-harvesting | D．invasive species |
| A．over-harvesting | B．sustainability |
| C．other species’ invasion | D．pollution |
| A．Protecting medicinal plants has a long way to go. |
| B．Ghillean Prance is optimistic about medicinal plants’ future. |
| C．Local people don’t know how to protect medicinal plants. |
| D．China has made great progress in protecting medicinal plants. |
| A．Low-cost Cancer Treatment |
| B．The Importance of Sustainability |
| C．Medicinal Plants on Verge of Extinction |
| D．Sustainable Development of the Environment |
【推荐3】A smartphone program is helping scientists learn about changes taking place in nature. More than 100,000 citizen-scientists around the world are taking pictures of many kinds of plants and animals using a program called iNaturalist. The program gives researchers much information about where plants and animals live, and how a growing human population is changing plant and animal life.
In Arlington, Virginia, naturalists are making a record of the plants and animals that live in the heavily populated area.
Alonso Abugattas is the local government’s natural resources manager. He works to protect and improve Arlington’s natural spaces. The group is using the iNaturalist smartphone program to record its observations. Then iNaturalist users throughout the world can look at the images and try to help recognize them. The program records where and when the picture was taken. This lets experts like Abugattas and others create maps that show where plants and animals are living, and how that changes because of development and climate change. That is important in Arlington and around the world.
Scott Loarie is co-director of iNaturalist. He said species are dying at a faster speed than ever, and the mix of life on Earth is threatened. “And we’ve only begun to understand exactly how those ecosystems contribute to our food system, or human health—all these things that we depend on.”
Loarie says iNaturalist lets citizen-scientists help professional (专业的) scientists gather data of the wild plants and animals in the world. More than 100,000 iNaturalist observers on all seven continents have made more than four-and-a-half million observations. The information has been used in studies of other animals.
Alonso Abugattas says the group in Arlington recorded more than 450 kinds of animals and plants. “If you just open up your eyes to the natural world, you’d be amazed at what’s out there.”
1. Which of the following is the function of the iNaturalist smartphone program?| A．Creating maps to show climate change. |
| B．Reminding experts to make out the photos. |
| C．Marking the time and places of the photos. |
| D．Writing down the names of species in the photos. |
| A．The goal of iNaturalist. |
| B．The regret for dying species. |
| C．The importance of scientists. |
| D．The value of species to humans. |
| A．It calls on people in the world to change nature. |
| B．It directly helps professional scientists to gather data. |
| C．It gets wildlife information and data from all over the world. |
| D．It lets professional scientists pay attention to humans’ behaviors. |
| A．Two Heads Are Better Than One |
| B．A Cheap Way to Study Plants and Animals |
| C．Measures Are Being Taken to Protect Plants and Animals |
| D．Naturalists Use a Smartphone Programme to Take Photos of Wildlife |
【推荐1】If you’re gathering your teenage kids in the living room to watch “The Falcon and the Winter Soldier” on Disney+, just know there’s a good chance they’d rather be playing “Fortnite”, a popular game.
That could totally be the case according to a new study from a consulting firm in Deloitte, which analyzed the generational divide in at-home entertainment.
The study, based on an online survey of more than 2,000 consumers, showed preferences are changing rapidly between millennials and the younger generation when it comes to how they want to spend their leisure time.
For Gen Z, defined as those born from 1997 to 2007,video - whether movies or television shows - is not a priority, the study found. 26% of Gen Zers in the survey said playing video games as their favorite entertainment activity, compared to 14% for listening to music, 12% for browsing the Internet and 11% for engaging on social media. Only 10% said they would rather watch a movie or TV show at home.
That compares to millennials (born 1983 to 1996),18% of whom chose watching movies and TV shows as their preferred mode of entertainment. Video games were the the entertainment option of choice for 16% of millennials.
“Gen Z would much rather spend time gaming, listening to music or using social media,” Jana Arbanas, entertainment leader at Deloitte, said. “That was a really alarming contrast that we saw relative to the shift that's happening and how Gen Z will impact this industry.”
“Millennials took the behaviors they developed as teenagers, and they've taken them forward into their early 30s, and so if Gen Z is anything like that, their behaviors may change slightly, but I don't see a complete aging out of their behaviors,” said Kevin Westcott, technology, media and telecom leader.
1. What does paragraph 1 tell us about teenagers today?| A．They are addicted to Fortnite. | B．They prefer games to movies. |
| C．They don't like being told what to do. | D．They tend to spend leisure time alone. |
| A．It will offer fewer games and more music. | B．It will see a decline in the use of social media. |
| C．It will be impacted by the need of millennials. | D．It will be influenced by the preference of Gen Zers. |
| A．They may outgrow their behaviors over time. |
| B．They’ll stop watching movies and TV shows. |
| C．They may not change much in their behaviors. |
| D．They’ll develop the same behaviors as millennials. |
| A．A medical report. | B．A shopping website. |
| C．A popular newspaper. | D．An entertainment fiction. |
【推荐2】Scientists have uncovered a fast-food eatery in the ancient Roman town of Pompeii. The remains help with the understanding of foods of Pompeii’s citizens.
About 80 such fast-food eateries have been found at Pompeii. But the latest find means this is the first time such a hot-food-drink eatery – known as a thermopolium – has been completely unearthed. Pompeii was destroyed by the volcanic eruption of Mount Vesuvius. Part of the fast-food counter was dug up in 2019 during work to shore up Pompeii’s ruins.
Since then, archaeologists (考古学家) have kept digging, uncovering a multi-sided-counter, with typical wide holes on its top, not unlike these for soup containers put into modern-day salad bars. The front of the counter included works of art showing ducks and chickens. The images brightened the eatery and also likely advertised food. Another image of a dog with a rope around its neck may remind people to keep pets tied up.
Early studies confirm “how the painted works represent, at least in part, the foods and drinks effectively sold inside”, said Valeria Amoretti, an anthropologist at Pompeii. Amoretti noted small pieces of duck bones were found in a food container. Remains of goats, pigs, and fish also were found. At the bottom of a wine container were remains of ground fava beans.
Massimo Osanna added, “We know what they were eating that day.” He was talking about the day of Pompeii destruction. The food remains are examples of “what’s popular with the common folk”. He added that wealthy Romans did not eat at such street-food businesses. Successful restaurant owners know that a good location is important for business. Osanna noted that right outside the eatery was a small square with a fountain. Another thermopolium was nearby.
1. What can we know about the fast-food eatery?| A．It was the only thermopolium at Pompeii. | B．It was dug up by accident at the beginning. |
| C．It once was one of the most popular eateries. | D．It was the first hot-food-drink eatery unearthed. |
| A．They helped to beautify the countertop area. |
| B．The volcanic eruption damaged the counter. |
| C．They were used to hold containers for hot food. |
| D．Food could be stored for a longer time with them. |
| A．Menus. | B．Reminders. | C．Decorations. | D．Advertisements. |
| A．The eatery reveals the local’s dining preference. |
| B．Ancient Romans liked eating at eateries. |
| C．Street-food business was rare in ancient Rome. |
| D．Food of Pompeii’s citizens was similar to today’s. |
【推荐3】Would it surprise you to learn that the vast majority of adults—around 75 per cent—tell up to two lies every day? That’s according to a recent US study. What this suggests then is that you’ve probably told a lie or two in the past 24 hours and chances are you’ve also been lied to.
Before you start protesting your innocence or confronting loved ones and colleagues, though, it’s worth noting that the bulk of these lies fall into the “hardly worth mentioning” category. Think little white lies such as attempting to spare someone’s feelings or gently twisting the facts to avoid looking bad.
People tell lies for a variety of reasons, say the US researchers. Just over 20 percent are told in a bid to avoid other people; a further 20 percent are jokes; 14 percent are told in self-protection; 13 percent are attempts to make a good impression; 11 percent are told to protect others; and 9 percent are for personal gain. Still, less than 12 percent of lies can be categorized as “big lies”— and these are usually the ones that really matter. An example of a big lie, according to the study’s authors, would be saying “I love you” without being sincere.
So, are there any body language giveaways that can help “out” someone who’s lying? Back in 2015, University of Michigan researchers identified some common behaviors among liars, including frowning or grimacing (扮怪相), looking directly at the questioner in a bid to appear trustworthy, and overcompensating by gesturing with both hands. A more recent study, from Erasmus University in Rotterdam, found that liars may unconsciously mimic the body language of those around them while their brains are otherwise engaged in telling lies. It’s also worth looking out for the “eye dart”: when we glance to the left, we’re attempting to recall facts and events; when we look to the right, we’re thinking more creatively.
Vocal factors can offer a good clue, too. People who are being deliberately dishonest — or who lack certainty in what they’re saying — tend to speak slower and place less emphasis on the middle of words, according to a study at the Sorbonne University in Paris. Interestingly, the researchers also found that listeners automatically registered these voice changes as a sign of dishonesty, even when they weren’t being asked to do so.
Earlier studies have suggested that we may know intuitively when someone is lying. It’s important to remember though that none of these pointers offer undeniable evidence that you’re dealing with a liar. After all, some people just grimace more or speak slower than others.
1. Which of the following lies are not categorized as “hardly worth mentioning”?| A．“I love your new haircut.” |
| B．“Relax. It makes no difference to me.” |
| C．“I am so into you.” |
| D．“My train was cancelled” instead of “I overslept and missed my train”. |
| A．He looks directly at the questioner to show his trust in him. |
| B．He unintentionally repeats the gesture made by the person he talks to. |
| C．He keeps glancing to the left from time to time when he talks. |
| D．He speaks slower and emphasizes the middle of the words less. |
| A．On average, all of us are lied to once or twice a day. |
| B．Most of the lies are told for the benefit of others. |
| C．A liar tends to gesture too much with both hands when he lies. |
| D．A dishonest man lacks certainty in what he’s saying. |
| A．We should rely on our intuition when spotting a liar. |
| B．Body language alone can serve as a sign of dishonesty. |
| C．Those who grimace more while speaking must be a liar. |
| D．There is no reliable pointer to identify a liar. |
