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 . A few years ago, the City Council of Monza, Italy, barred pet owners from keeping goldfish in curved fishbowls. The sponsors of the measure explained that it is cruel to keep a fish in such a bowl because the curved sides give the fish a distorted view of reality. Aside from the measure’s significance to the poor goldfish, the story raises an interesting philosophical question: How do we know that the reality we perceive is true?
Physicists are finding themselves in a similar trouble to the goldfish’s. For decades they have been pursuing an ultimate theory of everything—one complete and consistent set of fundamental laws of nature that explain every aspect of reality. It now appears that this pursuit may generate not a single theory but a family of interconnected theories, each describing its own version of reality, as if it viewed the universe through its own fishbowl. This concept may be difficult for many people to accept. Most people believe that there is an objective reality out there and that our senses and our science directly convey (传达) information about the material world. In philosophy, that belief is called realism.
In physics, realism is becoming difficult to defend. Instead, the idea of alternative realities is a mainstay of today’s popular culture. For example, in the science-fiction film The Matrix the human race is unknowingly living in a simulated (模拟的) virtual reality created by intelligent computers. How do we know we are not just computer-generated characters living in a Matrix-like world? If—like us—the beings in the simulated world could not observe their universe from the outside, they would have no reason to doubt their own pictures of reality.
Similarly, the goldfish’s view is not the same as ours from outside their curved bowl. For instance, because light bends as it travels from air to water, a freely moving object that we would observe to move in a straight line would be observed by the goldfish to move along a curved path. The goldfish could form scientific laws from their frame (框架) of reference that would always hold true and that would enable them to make predictions about the future motion of objects outside the bowl. If the goldfish formed such a theory, we would have to admit the goldfish’s view as a reasonable picture of reality.
The goldfish example shows that the same physical situation can be modeled in different ways, each employing different fundamental elements and concepts. It might be that to describe the universe we have to employ different theories in different situations. It is not the physicist’s traditional expectation for a theory of nature, nor does it correspond to our everyday idea of reality. But it might be the way of the universe.
1. What does the underlined word “distorted” in Paragraph most probably mean?A.Original. | B.Accurate. | C.Distant. | D.False. |
A.The need for a complete theory. | B.The lasting conflict in physics. |
C.The existence of the material world. | D.The conventional insight of reality. |
A.Nature’s mysteries are best left undiscovered. |
B.An external world is independent of the observers. |
C.People’s theories are influenced by their viewpoints. |
D.It is essential to figure out which picture of reality is better. |
A.various interpretations of the universe are welcomed |
B.physicists have a favorite candidate for the final theory |
C.multiple realities can be pieced together to show the real world |
D.there is still possibility to unify different theories into a single one |
6 . 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. |
7 . After five long years, it appears California’s drought is finally becoming less severe.
The state’s water struggles,
The quick inrush of water has also created a(n)
For now, though, Jones is focused on planning and ensuring the state’s water supply whatever may happen. “We’re halfway through our wettest season, and conditions have been encouraging,” she says. “I would say we’re
A.According to | B.With respect to | C.Thanks to | D.In addition to |
A.official | B.exhaustible | C.unexpected | D.crucial |
A.experienced | B.improved | C.worsened | D.investigated |
A.pollution | B.restrictions | C.pressure | D.cycles |
A.nevertheless | B.therefore | C.meanwhile | D.moreover |
A.accurate | B.plentiful | C.consistent | D.emergent |
A.productive | B.unchangeable | C.progressive | D.unreliable |
A.fell behind | B.broke down | C.came about | D.took off |
A.Or else | B.In other words | C.At that point | D.Above all |
A.Literally | B.Contrarily | C.Historically | D.Consequently |
A.levels | B.formations | C.struggles | D.reserves |
A.random | B.delicate | C.mechanical | D.insensible |
A.heightens | B.assumes | C.minimizes | D.identifies |
A.restorations | B.calculations | C.conditions | D.projections |
A.hopelessly | B.extremely | C.guardedly | D.cheerfully |
8 . 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 |
9 . Million-year-old mammoth genomes push the limits of a revolutionary technique
In the 1966 science-fiction movie “One Million Years B.C. ”, Raquel Welch and John Richardson traverse a primitive landscape inhabited by dinosaurs and early humans. The film was low on science and high on
A more
The team’s work represents a new
The trouble with DNA is that it breaks down after death. The more brokendown it is, the
Samples were sent to Dr Dalen’s laboratory in 2017 and strands of DNA were extracted, sequenced, and dated. Whereas DNA samples from a living animal can run to several hundreds of thousands of letters, the timeworn mammoth samples
To date a specimen, fragments of its DNA are compared to corresponding chunks from
The teeth held other
A.novel | B.fiction | C.drama | D.research |
A.urgent | B.descriptive | C.particular | D.accurate |
A.record | B.term | C.admission | D.pioneer |
A.Revealed | B.Extracted | C.Enrolled | D.Injected |
A.popular | B.punctual | C.invaluable | D.realistic |
A.related | B.concerned | C.critical | D.silent |
A.harder | B.quicker | C.stronger | D.lower |
A.equivalent | B.comparison | C.variation | D.messenger |
A.moreover | B.therefore | C.however | D.meanwhile |
A.mined | B.yielded | C.overestimated | D.recited |
A.destination | B.location | C.limit | D.permit |
A.precious | B.lost | C.rotten | D.known |
A.manual | B.just | C.imperial | D.previous |
A.surprises | B.miracles | C.imaginations | D.alternatives |
A.suddenly | B.permanently | C.slowly | D.accidentally |
10 . 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 |