It is perhaps the most ironic symbol of the life on our planet. The Amazon is the world’s largest and most bio-diverse tropical rainforest and a huge trap for carbon dioxide. The harms of
Gati has spent years
That nightmare situation is the well-known Amazon
Warnings that this is approaching have now taken on extreme urgency. The rate of deforestation has increased sharply and is fast approaching the theoretical
Scientists first began to seriously worry about a potential Amazon tipping point in about 2000, when some studies warned that a combination of climate change and deforestation could cause the rainforest to
A few years later, a team of Brazilian scientists put numbers on it. They
The scientists have since
“Either way, we would be wise not to exceed 20%”, says a scientist, “for the commonsense reason that there is no point in
A.fertilization | B.elimination | C.deforestation | D.frustration |
A.program | B.disaster | C.protection | D.regulation |
A.evolution | B.spotlight | C.condition | D.emergency |
A.measuring | B.observing | C.protecting | D.criticizing |
A.released | B.melted | C.turned | D.supplied |
A.tipping | B.disappointing | C.awarding | D.tapping |
A.build | B.turn | C.cause | D.make |
A.problem | B.prediction | C.aspect | D.limit |
A.base | B.edge | C.surface | D.track |
A.dry out | B.run down | C.pay off | D.rise up |
A.boasted | B.insisted | C.estimated | D.instructed |
A.thirst | B.starvation | C.cold | D.disease |
A.digested | B.revised | C.encouraged | D.previewed |
A.strategy | B.climate | C.average | D.system |
A.diagnosing | B.instructing | C.inquiring | D.discovering |
2 . At first, the grains of rice that Ingo Potrykus held in his fingers did not seem at all
For more than a decade Potrykus had
At that point, he tackled an even greater challenge. The golden grains
The debate began the moment genetically engineered crops (GM crops) were first sold in the 1990s, and it has
The hostility is
The benefits did seem small
Many people
A.typical | B.special | C.local | D.white |
A.dreamed of | B.come in handy | C.been reminded of | D.broken up |
A.attempt at | B.effort to | C.resistance to | D.majority of |
A.But | B.And | C.While | D.Since |
A.surprise | B.obstacle | C.norm | D.opposition |
A.achieved | B.stressed | C.overlooked | D.contained |
A.was caught in | B.was alive with | C.be conscious of | D.was honored by |
A.announced | B.maintained | C.escalated | D.applied |
A.brilliant | B.understandable | C.discharged | D.rewarding |
A.introduced | B.reminded | C.respected | D.overlooked |
A.toss and turn | B.give and take | C.produce and sell | D.demand and supply |
A.until | B.after | C.although | D.when |
A.feature | B.mark | C.build | D.benefit |
A.worried about | B.ashamed of | C.filled with | D.admired for |
A.terror | B.misery | C.starvation | D.crisis |
3 . To prevent tsunami-caused disasters, several countries worked together to expand the use of a tsunami-detecting system that had been developed in the United States by the National Oceanic and Atmospheric Administration (NOAA). The system
By 2004 only six such detectors had been installed, all in the Pacific. There were
There are now 53 detector buoys operating in the world’s oceans, including 6 of a planned 27 in the Indian Ocean. So a (n)
In March, the system, which is run by the Japan Meteorological Agency (JMA), did not work perfectly. JMA’s initial
A.approves | B.rids | C.expects | D.consists |
A.broadcasts | B.foresees | C.assigns | D.imposes |
A.some | B.a few | C.none | D.others |
A.qualified | B.alerted | C.substituted | D.fueled |
A.although | B.until | C.as | D.where |
A.difficult | B.thoughtful | C.easy | D.pressing |
A.alternative | B.perspective | C.repetition | D.resume |
A.surprise | B.mistake | C.accident | D.force |
A.reference | B.confirmation | C.suggestion | D.expectation |
A.undertake | B.multiply | C.deposit | D.blanket |
A.location | B.direction | C.territory | D.length |
A.note | B.catalogue | C.volume | D.estimate |
A.worse | B.larger | C.higher | D.wider |
A.schedule | B.scheme | C.monitor | D.response |
A.warning | B.security | C.setting | D.responsibility |
4 . It has always been assumed that noise is a problem unique to animals. But a new study by Ali Akbar has revealed that plants suffer too.
That plants can be damaged indirectly by noise pollution has never been in doubt. Since most flowering species depend upon pollinators (授粉者) and most fruit-bearing species need animals to spread around their seeds, it is obvious that if these animal partners are harmed by noise then their botanical counterparts will do badly, too. What has remained unknown is whether or not plants themselves suffer directly from noise pollution.
Scientists have previously assumed that plants may be able to sense sound waves as they are struck by them. A number of experiments have confirmed this in recent years — plants heavily exposed to ultrasound in the lab have shown a range of negative responses including the expression of stress-related genes, slowed growth and reduced development of seeds.
Yet attacking plants with ultrasound is not the same as growing them in the presence of actual traffic noise. To this end, Ali Akbar decided to set up an experiment to study precisely this questions.
Working with a team of colleagues, he grew marigolds (孔雀草) and sage (鼠尾草) in his lab that are commonly found in urban environments. The plants were divided into two groups after getting mature. One group was exposed to 73 decibels of traffic noise. The other group was left to grow in silence. After 15 days had passed, samples were taken from the youngest fully expanded leaves on every plant in the experiment and studied.
None of the plants exposed to the traffic noise did well. Analysis of their leaves revealed that all of them were suffering. The team found that a range of hormones(荷尔蒙) normally associated with healthy growth and development in plants were present at significantly reduced levels in the plants exposed to the noise. Two stress hormones, which are normally produced to prevent insect attacks and deal with salty soil or very cold temperatures, were elevated.
Ali Akbar’s findings make it clear that though plants lack ears, the noise of traffic still bothers them enough to trigger dramatic stress responses that are not much different to those that would be found in plants exposed to drought, highly concentrated salt or heavy metals in their soil.
The next question is whether all noise pollution affects all species in the same way. The natural world is by no means silent. Whether some plant species have evolved coping mechanisms, which might one day be collected and transferred into urban-living species, is a mystery worth exploring.
1. What did scientists believe in the past?A.Noise is a problem directly facing both animals and plants. |
B.Plants can be affected by noise in an indirect way. |
C.Animal partners can do harm to their botanical partners. |
D.Sound waves can damage plants because they have senses. |
A.Ultrasound is similar to traffic noise in that it doesn’t harm plants. |
B.Plants exposed to ultrasound exhibit negative signs of growth. |
C.Traffic noise causes plants to grow unhealthily and slowly. |
D.Plant leaves contain hormones dealing with a harsh environment. |
A.Plants growing in silence have a reduced level of hormones |
B.Plants exposed to noise respond differently from those in drought. |
C.Different noise pollution has the same effect on all species. |
D.An increase in stress hormones in plants means they are in hardship. |
A.Some plants may not necessarily be harmed by the sound in nature. |
B.Some plants have surely developed a method to cope with traffic noise. |
C.Unban-living species can be engineered to grow well in the natural world. |
D.The silence in nature promotes the development of noise coping mechanisms. |
5 . When it comes to black holes, we are caught between a rock and a hard place. In the 1970s, Stephen Hawking showed that all black holes give off thermal radiation(热辐射)and eventually evaporate(蒸发). In doing so, they seemed to be destroying information contained in the matter that fell into them, therefore going against a rule of quantum mechanics(量子力学): information cannot be created or destroyed.
Some argued that the outgoing “Hawking radiation” preserved the information. However, if this were the case, then given certain assumptions, the event horizon(视界)—— the black hole’s boundary of no return—— would become intensely energetic, forming a firewall. But such firewalls go against the theory of general relativity, which says that space-time near the event horizon should be smooth. The black hole firewall paradox was thus born.
Now, Sean Carroll at the California Institute of Technology and his colleagues have shown that the paradox disappears when the evolution of black holes is understood in the context of the many-worlds interpretation of quantum mechanics.
The quantum state of the universe is described by something called the global wave function(全局波函数). According to traditional quantum mechanics, whenever there are many possible outcomes for physical process, this wave function ”collapses“ to represent one outcome. But in the many-worlds Interpretation, the wave function doesn’t collapse-rather, it branches, with one branch for each outcome. The branches evolve independently of each other, as separate worlds.
In this way of thinking, the formation of a black hole and its evaporation due to Hawking radiation lead to multiple branches of the wave function. An observer monitoring a black hole also splits into multiple observers, one in each branch.
The new work shows that from the perspective of an observer in a given branch, space-time behaves as described by general relativity and the black hole has no firewall.
But does that imply loss of information? No, says team member Aidan Chatwin-Davies, also of Caltech. That is because the principle of preservation of information applies to the global wave function and not to its individual branches, he says. Information is preserved across all branches of the global wave function, but not necessarily in any one branch. Given this case, a black hole that doesn’t lose information and yet has a smooth, uneventful event horizon without a fire wall isn’t a contradiction.
Yasunori Nomura at the University of California at Berkeleyy has independently arrived at some similar conclusions in his work. He agrees that the many-worlds approach resolves the paradox around information loss from black holes. “Many worlds should be taken seriously,” he says.
1. Which word in the article is similar in meaning to the underlined word in Paragraph 2?A.Assumption (Paragraph 2) | B.Interpretation (Paragraph 4) |
C.Evaporation (Paragraph 5) | D.Contradiction (Paragraph 7) |
A.There is a firewall. | B.No observer will split. |
C.No information is lost. | D.The wave function collapses. |
A.introduce an independent scientist |
B.support the many-worlds interpretation |
C.question whether many worlds really exist |
D.argue against the information loss from black holes |
A.Rules of quantum mechanics. |
B.A new understanding of the black hole. |
C.Hawking’s interpretation of the black hole. |
D.The development of the global wave function. |
6 . The news that Derby has approved what promises to be Britain’s largest urban rewilding project so far is very welcome. The 320-hectare Allestree Park will, subject to detailed consultation, be given over to a range of habitats and perhaps even see the reintroduction of species such as dormice and red kites.
Urban rewilding - which is not the same as urban green space, however extensive - can take many forms. They
But in fact, some of the most successful projects have been
Urban rewilding,
The pressure for development means that there will always be tension with
In these mid-pandemic, post-Brexit, austerity-bitten (财政紧缩的) times, the financial arguments can be hardest to
A.differ | B.originate | C.range | D.develop |
A.transporting | B.attaching | C.leading | D.transforming |
A.mature | B.established | C.reputational | D.accidental |
A.specifically | B.fundamentally | C.previously | D.primarily |
A.bring about | B.serve as | C.contribute to | D.rely on |
A.breeding | B.launching | C.introducing | D.favoring |
A.by contrast | B.for instance | C.in itself | D.in the meanwhile |
A.appreciations | B.perceptions | C.insights | D.recovery |
A.encounter | B.sustain | C.create | D.promote |
A.recreational | B.political | C.industrial | D.commercial |
A.qualified | B.maintained | C.reserved | D.cultivated |
A.linked to | B.inseparable from | C.dismissed as | D.equivalent to |
A.value | B.profit | C.benefit | D.worth |
A.approve | B.counter | C.settle | D.consider |
A.fundamental | B.essential | C.overwhelming | D.obvious |
7 . Sea levels along coastlines in the United States will rise about one foot by 2050, with larger increases on the East and Gulf coasts, according to a comprehensive new report by climate scientists.
Oceans have already risen about one foot in the last century, as climate change melts glaciers (冰川) and ice caps around the world. But the pace is
The report gives the most concrete and certain sea level
Sea level rise
The new report adds up all those factors to give
Sea level rise is happening more
William Sweet, a sea level rise expert with the National Oceanic and Atmospheric Administration (NOAA) and one of the authors of the new report, says cities that are not yet flooded should
Beyond 2050, the report makes clear that humans have a
A.dying down | B.paying back | C.holding on | D.speeding up |
A.records | B.extremes | C.predictions | D.solutions |
A.flexibly | B.clearly | C.randomly | D.incredibly |
A.continues | B.impacts | C.multiplies | D.varies |
A.added | B.drained | C.spilt | D.needed |
A.creatures | B.currents | C.ecosystems | D.voyages |
A.stable | B.crucial | C.unlikely | D.worse |
A.national | B.regional | C.apparent | D.approximate |
A.dig | B.turn | C.collapse | D.dive |
A.similar | B.scenery | C.distant | D.diverse |
A.projected | B.obliged | C.permitted | D.noticed |
A.sharply | B.mysteriously | C.unexpectedly | D.slowly |
A.make sense | B.take notice | C.keep pace | D.stay proud |
A.scheme | B.cancel | C.change | D.delay |
A.promise | B.quarrel | C.choice | D.protest |
8 . When Mexican scientist of the evolution of animal behavior, Laura Cuaya, moved to Hungary for her postdoctoral studies in Budapest, she brought her pet dog, Kun-kun, along for the ride. Cuaya couldn't help noticing how locals warmed to dogs. This prompted her naturally curious scientific mind to start asking questions. “Here people are talking all the time to Kun-kun, but I always wonder if Kun-kun can recognize that people in Budapest speak Hungarian, not Spanish?” So she set out to find an answer through a scientific study.
Cuaya and her colleagues decided to use brain images from MRI scanning to shed light on her hunch. They worked with dogs of various ages that had, until the experiment, only heard their owners speak just one of the two languages, Spanish or Hungarian. Not surprisingly, getting the dogs to happily take part in the experiment took some creative coaxing and animal training! The researchers first needed to teach Kun-kun and her 17 fellow participating dogs including a labradoodle, a golden retriever and Australian shepherds, to lie still in a brain scanner. Their pet parents were always present, and they could leave the scanner at any point.
The research team played children's book classic The Little Prince in both Spanish and Hungarian while scanning the dogs' brains with an MRI machine. They were looking for evidence that their brains reacted differently to a familiar and unfamiliar language. The researchers also played scrambled versions of the story to find out if dogs could distinguish between speech and non-speech.
The images reveal that dogs' brains show different patterns of activity for an unfamiliar language than for a familiar one — the first time anyone has proved, researchers say, that a non-human brain can distinguish between two languages. This means that the sounds and rhythms of a familiar language are accessible to non-humans.
Interestingly, the team also found that the brains of older dogs were more skilled at detecting speech “suggesting a role for the amount of language exposure”. They suggest that dogs have refined their ability to distinguish between human languages over the long process of domestication.
1. What is paragraph 1 mainly about?A.The background of the study. | B.The significance of the study. |
C.The concern of the researcher. | D.The introduction to the researcher. |
A.Age limits. | B.Brain patterns. | C.Language exposure. | D.Owners' commands. |
A.practical | B.contradictory | C.compromising | D.groundbreaking |
A.Dogs Can Tell Foreign Languages | B.Dog Brains Have Different Patterns |
C.Old Dogs Know More About Human Speech | D.Dogs Can Differ Speech From Non-Speech |
What Can One City Do?
People around the world are concerned about global warming and are talking about ways to stop it. The city of Cambridge, Massachusetts, in the United States, is doing more than just talking. Cambridge wants to become a world leader in energy-efficient buildings.
Today, Naema Omar is improving her 80-year-old house in Cambridge. To keep the heat inside in the winter, she is filling the space inside the walls with insulation(绝缘). Insulation is usually made from chemicals, but in her house, she is using
But eco-friendly insulation and lighting are much more expensive than the usual kind
It was ten years ago that the city of Cambridge decided to try to reduce its carbon emissions. More than 80 percent of the carbon dioxide
10 . Brazil’s election offers hope for the rainforest
A presidential election in 2022 will offer a chance for Brazil’s government to reverse policies that have
On his watch, environmental enforcement and fines dropped to record lows. Activists say this has encouraged
A greener president would try to crack down on such crimes. Polls
But even an enlightened president will have to battle a
Better leadership in Brazil could jump-start regional efforts to boost enforcement and find sustainable
A.referred | B.contributed | C.amounted | D.related |
A.footprint | B.sink | C.source | D.emission |
A.indeed | B.instead | C.accidentally | D.otherwise |
A.stepped down | B.took office | C.claimed precedence | D.kept watch |
A.seasonal | B.selective | C.illegal | D.professional |
A.involvement | B.attachment | C.limitation | D.existence |
A.advise | B.advocate | C.suggest | D.represent |
A.sustainable | B.economic | C.rapid | D.rural |
A.claim | B.manage | C.create | D.borrow |
A.farmer-friendly | B.warm-blooded | C.pressure-free | D.profit-making |
A.realise | B.normalize | C.publicise | D.legalise |
A.sold | B.explored | C.cleared | D.occupied |
A.election | B.argument | C.appeal | D.decision |
A.main | B.varied | C.final | D.same |
A.replacements | B.transitions | C.alternatives | D.references |