1 . Early fifth-century philosopher St．Augustine famously wrote that he knew what time was unless someone asked him．Albert Einstein added another wrinkle when he theorized that time varies depending on where you measure it．Today's state-of-the-art atomic（原子的） clocks have proven Einstein right．Even advanced physics can't decisively tell us what time is, because the answer depends on the question you're asking．
Forget about time as an absolute．What if，instead of considering time in terms of astronomy,we related time to ecology？What if we allowed environmental conditions to set the tempo（节奏） of human life？We're increasingly aware of the fact that we can't control Earth systems with engineering alone，and realizing that we need to moderate（调节）our actions if we hope to live in balance．What if our definition of time reflected that？
Recently，I conceptualized a new approach to timekeeping that's connected to circumstances on our planet，conditions that might change as a result of global warming．We're now building a clock at the Anchorage Museum that reflects the total flow of several major Alaskan rivers，which are sensitive to local and global environmental changes．We've programmed it to match an atomic clock if the waterways continue to flow at their present rate．If the rivers run faster in the future on average，the clock will get ahead of standard time．If they run slower，you'll see the opposite effect．
The clock registers both short-term irregularities and long-term trends in river dynamics．It's a sort of observatory that reveals how the rivers are behaving from their own temporal frame（时间框架），and allows us to witness those changes on our smartwatches or phones．Anyone who opts to go on Alaska Mean River Time will live in harmony with the planet．Anyone who considers river time in relation to atomic time will encounter a major imbalance and may be motivated to counteract it by consuming less fuel or supporting greener policies．
Even if this method of timekeeping is novel in its particulars，early agricultural societies also connected time to natural phenomena．In pre-Classical Greece，for instance，people“corrected”official calendars by shifting dates forward or backward to reflect the change of season．Temporal connection to the environment was vital to their survival．Likewise，river time and other timekeeping systems we're developing may encourage environmental awareness．
When St．Augustine admitted his inability to define time， he highlighted one of time 's most noticeable qualities：Time becomes meaningful only in a defined context．Any timekeeping system is valid，and each is as praiseworthy as its purpose．
1. What is the main idea of Paragraph 1？| A．Timekeeping is increasingly related to nature． |
| B．Everyone can define time on their own terms． |
| C．The qualities of time vary with how you measure it． |
| D．Time is a major concern of philosophers and scientists． |
| A．present an assumption | B．evaluate an argument |
| C．highlight an experiment | D．introduce an approach |
| A．Those who do not go on river time will live an imbalanced life． |
| B．New ways of measuring time can help to control Earth systems． |
| C．Atomic time will get ahead of river time if the rivers run slower． |
| D．Modern technology may help to shape the rivers’ temporal frame． |
| A．It is crucial to improve the definition of time． |
| B．A fixed frame will make time meaningless． |
| C．We should live in harmony with nature． |
| D．History is a mirror reflecting reality． |
2 . Steven Stein likes to follow garbage trucks. His strange habit makes sense when you consider that he’s an environmental scientist who studies how to reduce litter, including things that fall off garbage trucks as they drive down the road. What is even more interesting is that one of Stein’s jobs is defending an industry behind the plastic shopping bags.
Americans use more than 100 billion thin film plastic bags every year. So many end up in tree branches or along highways that a growing number of cities do not allow them at checkouts(收银台). The bags are prohibited in some 90 cities in California, including Los Angeles. Eyeing these headwinds, plastic-bag makers are hiring scientists like Stein to make the case that their products are not as bad for the planet as most people assume.
Among the bag makers’ argument: many cities with bans still allow shoppers to purchase paper bags, which are easily recycled but require more energy to produce and transport. And while plastic bags may be ugly to look at, they represent a small percentage of all garbage on the ground today.
The industry has also taken aim at the product that has appeared as its replacement: reusable shopping bags. The stronger a reusable bag is, the longer its life and the more plastic-bag use it cancels out. However, longer-lasting reusable bags often require more energy to make. One study found that a cotton bag must be used at least 131 times to be better for the planet than plastic.
Environmentalists don’t dispute(质疑) these points. They hope paper bags will be banned someday too and want shoppers to use the same reusable bags for years.
1. What has Steven Stein been hired to do?| A．Help increase grocery sales. |
| B．Recycle the waste material. |
| C．Stop things falling off trucks. |
| D．Argue for the use of plastic bags. |
| A．Bans on plastic bags. |
| B．Effects of city development. |
| C．Headaches caused by garbage. |
| D．Plastic bags hung in trees. |
| A．They are quite expensive. |
| B．Replacing them can be difficult. |
| C．They are less strong than plastic bags. |
| D．Producing them requires more energy. |
| A．Plastic, Paper or Neither |
| B．Industry, Pollution and Environment |
| C．Recycle or Throw Away |
| D．Garbage Collection and Waste Control |
3 . I’ve been in an 18-year love-hate relationship with a black walnut tree.
It’s a unique tree. In late September or early October, falling fruits as hard as baseballs threaten the skulls (头骨) of you, your children, your neighbors and those that reside next door to them. Umbrellas in the yard are a must while dining in early August, and as for me, I wear my bike helmet while working in the garden.
The black walnut also releases a chemical substance through its roots as a competitive strategy. It’s poisonous to several common plants. There have been many new plant varieties that I brought home with hopes that maybe the black walnut would accept them, but they failed to flourish.
What does work are native plants that naturally grow in the area. Native plants are important to have around since they provide beneficial pollinators (传粉者) like birds, bees and butterflies with seeds and contribute to a healthy and biodiverse environment. Native plants for this area are generally easy to grow, so they experience less stress.
Have I thought of getting rid of this giant pain in my tiny backyard? Yes, however, getting rid of this tree standing at 50 feet with an 87-inch trunk is next to impossible. It’s also protected under the law. Rightfully so. Trees are important to the urban forest and for all of those that inhabit it.
Sometimes I think about my life without the black walnut. I can’t imagine a spring without the birds who arrive every year and loudly sing their songs before dawn. I’d miss falling asleep on lazy weekend afternoons as I look up into its leaves.
Every spring, I wonder what the season holds: What are the chances of being knocked unconscious while barbecuing? Like any good relationship, I’ll never be pleased. I’m stuck with this tree, so I’ll listen to its needs and give it the space it requires. In return, my walnut offers a habitat for wildlife and a reminder.
1. Why does the author wear a bike helmet while working in the garden?| A．To protect the injured skull. | B．To prevent herself from sunburn. |
| C．To avoid being hit by the nuts. | D．To reduce the chance of getting bitten by bees. |
| A．It attracts beneficial pollinators. |
| B．It lets out poison to drive away pests. |
| C．It produces a chemical fatal to some plants. |
| D．It competes for nutrition with similar species. |
| A．The volume of its fruits may bring inconvenience. |
| B．The tree outcompetes the native plants in the garden. |
| C．The tree is home to numerous birds and other creatures. |
| D．The presence of the tree takes up much space of the garden. |
| A．it’s better to give than to take |
| B．trees and plants have their own ways to flourish |
| C．even a good relationship is not always trouble-free |
| D．acceptance, instead of resistance, is the better way to be |
4 . 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 |
5 . More than a score of Australian rare mammals have been killed by wild cats. These predators, which arrived with European settlers, still threaten native wildlife — and are too plentiful on the mainland to eliminate, as has been achieved on some small islands which were previously filled with them. But Alexandra Ross of the University of New South Wales thinks she has come up with a different way to deal with the problem. As she writes in a paper in the Journal of Applied Ecology, she is giving feline (猫科的) — awareness lessons to wild animals involved in re-introduction programs, in order to try to make them cat-conscious.
Many Australian mammals, though not actually extinct, are restricted to fragments of cat-free habitat. This will, however, put the forced migrants back in the sights of the cats that caused the problem in the first place. Training the migrants while they are in captivity, using stuffed models and the sorts of sounds made by cats, has proved expensive and ineffective. Ms Ross therefore wondered whether putting them in large natural enclosures with a scattering of predators might serve as a form of training camp to prepare them for introduction into their new, cat-ridden homes.
She tested this idea on a type of bandicoot (袋狸) that superficially resembles a rabbit. She and her colleagues raised two hundred bandicoots in a huge enclosure that also contained five wild cats. As a control, she raised a nearly identical population in a similar enclosure without the cats. She left the animals to get on with life for two years, which, given that bandicoots breed four times a year and live for around eight years, was a considerable period for them. After some predation (扑食) and probably some learning, she abstracted 21 bandicoots from each enclosure, attached radio transmitters to them and released them into a third enclosure that had ten hungry cats in it. She then monitored what happened next. The outcome was that the training worked. Over the subsequent 40 days, ten of the untrained animals were eaten by cats, but only four of the trained ones. One particular behavioral difference she noticed was that bandicoots brought up in a predator-free environment were much more likely to sleep alone than were those brought up around cats. And when cats are around, sleeping alone is dangerous. How well bandicoots that have undergone this extreme training will survive in the wild remains to be seen. But Ms Ross has at least provided reason for hope.
1. What can be learned from the first paragraph?| A．The feline-awareness lessons have proved ineffective. |
| B．There are too many wild cats to be killed in Australia. |
| C．Different ways have been tried to hunt and kill wildlife. |
| D．Native wildlife has been threatened by a growing population of wild cats. |
| A．Australian mammals restricted to certain areas |
| B．The wild cats tracking down the mammals |
| C．Wild animals involved in the program |
| D．The predators captured by the animal trainers |
| A．They were both closely monitored. | B．They had 200 bandicoots in total. |
| C．They had similar natural environment. | D．They both had wild cats in them. |
| A．Untrained bandicoots failed to identify cats. |
| B．Training bandicoots prepared them to fight cats. |
| C．Sleeping alone in the wild was dangerous. |
| D．Bandicoots could be trained to avoid predators. |
6 . In the 1966 science-fiction movie One Million Years B. C., the movie characters had a time travel and arrived in an ancient landscape inhabited by dinosaurs and early humans. The movie was low on science and high on fiction: by then dinosaurs were long dead and modern humans were millions of years away.
A more accurate picture of Earth’s inhabitants at the time is now being revealed. In research published in Nature, a team of scientists led by Anders Gotherstrom at the University of Stockholm, and Love Dalen at the Centre for Palaeogenetics (古遗传学), also in Sweden, describe sequencing (测序) DNA samples from mammoths (猛犸象) that lived and died in north-eastern Siberia around a million years ago.
The team’s work represents a new record, for their mammoth DNA is, by some half a million years, the oldest ever successfully reconstructed. Extracted (提取) from horses, bears and even Neanderthals and Denisovans, two close cousins of modern humans, such ancient DNA has proved an invaluable tool for investigating the past. Although fossils preserve the basic physical features of extinct animals, they are silent about many crucial details that even an incomplete genome (基因组) can help to fill in.
The trouble with DNA is that it breaks down after death. The more broken down it is, the harder it is to sequence. Scientists think that, after about 6m years, all that would be left would be individual base pairs (碱基对), the equivalent of trying to reconstruct a book from several letters. Under the right conditions, however, such as the extreme cold of Arctic permafrost (冻土层) this decay can be slowed.
Dr. Dalen and his colleagues were interested in three mammoth molars (臼齿) extracted in the 1970s from Siberian geological layers that suggested great age. Samples from each were sent to Dr. Dalen’s laboratory in 2017. Having checked they had not been contaminated by bacteria or the shaking hands of Paleontologists, the DNA were extracted, sequenced, and dated. Whereas DNA samples from a living animal can run to several hundreds of thousands of letters, the ancient mammoth samples yielded merely dozens of letter long. This is close to the limit of what is scientifically usable, says a biologist named Ludovic Orlando.
1. What does the underlined word “contaminated” probably mean?| A．Protected. | B．Polluted. | C．Estimated. | D．Discovered. |
①the limited number of DNA in mammoth samples
②the break-down of mammoth’s DNA after death
③the wide spread of mammoth samples
④the damage done to the mammoth samples from external environment
⑤the difficulty in extraction of the mammoth’s DNA
| A．①②④ | B．②④⑤ | C．②③④ | D．①③④ |
| A．The fact that DNA can break down makes it easier to sequence. |
| B．The incomplete genome can’t give any details of the extinct animals. |
| C．Mammoths’ DNA samples are invaluable for their extremely long history. |
| D．The research team created a new record for reconstructing an ancient book. |
| A．The movie One Million Years B. C revealed the early human civilization. |
| B．Scientists have uncovered the secrets of life by studying mammoths’ DNA. |
| C．The mammoths’ DNA may give a clearer picture of ancient inhabitants on earth. |
| D．Discoveries of mammoths’ DNA samples help the development of DNA reconstruction technology. |
7 . Biodiversity is a concept that's commonly referenced, yet regularly misunderstood. The complex
“If biodiversity disappears, so do people,” says Dr. Stephen Woodley, field ecologist and bio-diversity expert with the International Union for Conservation of Nature. “We are part of the
Preventing such a catastrophe, says Woodley, begins with understanding why biodiversity is declining, and then taking action to
“The two greatest
That's the mission of the global Campaign for Nature, a partnership of the Wyss Foundation and the National Geographic Society. Instead of simply protecting 30 percent of the Earth, the
The campaign also recognizes the importance of
“Biodiversity is stability,” says Sala. “Trees, wetlands, grasslands, peat bogs(泥炭沼泽), salt marshes(盐沼), healthy ocean ecosystems, mangroves(红树林), and plants
| A．argument | B．term | C．structure | D．problem |
| A．altering | B．developing | C．stabilizing | D．worsening |
| A．ecosystem | B．threat | C．cycle | D．procedure |
| A．affect | B．change | C．reverse | D．continue |
| A．aspects | B．causes | C．consequences | D．occasions |
| A．acquiring | B．protecting | C．exploiting | D．possessing |
| A．management | B．announcement | C．campaign | D．competition |
| A．consume | B．destroy | C．lose | D．contain |
| A．denying | B．enjoying | C．ignoring | D．respecting |
| A．essential | B．simple | C．temporary | D．profitable |
| A．Besides | B．However | C．Thus | D．Otherwise |
| A．witness | B．detect | C．confirm | D．avoid |
| A．measure | B．absorb | C．survive | D．prevent |
| A．mission | B．decision | C．option | D．exploration |
| A．worried about | B．confident in | C．responsible for | D．good at |
Forests give us shade, quiet and one of the harder challenges in the fight against climate change. Even as we humans count on forests to soak up a good share of the carbon dioxide we produce, we
Thankfully, there is a way out of this trap—but it involves striking a subtle balance. Helping forests flourish as valuable “carbon sinks” long into the future
The state's proposed Forest Carbon Plan aims to double efforts
The need
California plans to treat 35,000 acres of forest a year by 2020, and 60,000 by 2030—financed from the proceeds of the state's emissions-permit auctions. That's only
State governments are well accustomed to managing forests,
9 . Scientists say record heat has cost reef half of corals
The Great Barrier Reef, one of the earth's most precious habitats, lost half of its coral populations in the last quarter-century, a decline that researchers in Australia said would continue unless drastic action is taken to reduce the effects of climate change.
Colony sizes were smaller, there were fewer “big mamas," or older large corals that produce baby corals; and there were fewer of those babies, which are vital to the reefs future ability to
“There is no time to
Researchers were disappointed about what they saw as a lack of attention to the study from government leaders in Australia, the world's biggest coral exporter. The government has
The Great Barrier Reef, which
"You can
Coral reefs worldwide are
“The situation is serious," Professor Burkepile said. But people should not feel
At the local level,
| A．live | B．manufacture | C．return | D．breed |
| A．in terms of | B．in relation to | C．in comparison with | D．with regard to |
| A．Fading | B．Failing | C．Collapsing | D．Poisoning |
| A．accustomed | B．subjected | C．elevated | D．adapted |
| A．drivers | B．resources | C．consequences | D．aspects |
| A．lose | B．act | C．wait | D．miss |
| A．raised | B．handled | C．received | D．resisted |
| A．supports | B．undergoes | C．survives | D．accommodates |
| A．literally | B．alternatively | C．automatically | D．particularly |
| A．responsible | B．profitable | C．available | D．sustainable |
| A．suspicious | B．hesitant | C．hopeless | D．careless |
| A．exclusive | B．aggressive | C．oppressive | D．excessive |
| A．for example | B．in fact | C．on the contrary | D．in turn |
| A．strengthens | B．weakens | C．worsens | D．exaggerates |
| A．inherit | B．recover | C．grow | D．prosper |
10 . During those barren winter months, with windows overlooking long-dead gardens, leafless trees, and lawns that seem to have an ashy look about them, nothing calms the uneasy nerves more than the vibrant green of plants surrounding the living spaces of one’s home. People browse through garden stores just to get a smell of chlorophyll (叶绿素) and to choose a plant or two to bring spring back into their winter-gray lives.
Now there is even more of a need for “the green,” in light of recent articles warning us of the dangers of chemicals that we, ourselves, introduce into our homes. Each time we bring clothes home from the cleaners, we release those chemicals into the closed-in air of our homes. Every cleanser releases its own kind of fumes.
Some of the chemicals are formaldehyde (甲醛), chlorine, benzene, styrene, etc. Read the labels on many home products, the ingredients aren’t even listed! During the winter, when those same windows are shut tight, we breathe in these chemicals—causing symptoms much like allergies (过敏). In fact, most people probably dismiss the effects of these chemicals simply as some allergy or other. The truth is that we are experiencing a syndrome that is called Multiple Chemical Sensitivity. Now, what has this got to do with green plants? Everything healthy! Research has been conducted with two types of plants that have actually removed much of these harmful chemicals from the air.
The two plants that seem to be the best bet for ridding one’s home of such chemicals are ferns (蕨类植物) and palms. These plants release moisture as part of photosynthesis and, as they do, pull chemicals from the air into their leaves. Even NASA has conducted some greenhouse experiments for long-term space exploration. Within hours, their plants [palms] had removed almost all traces of formaldehyde in the room. Both species of plants are ancient, dating back more than a hundred million years. Another trait they share is that they both live long lives, 100 years or more. This we expect from trees, but ferns and palms are plants; plants that can grow to 65 feet in the proper setting! Even their individual leaves live for one to two years [ferns] and one to nine years [palms]. Perhaps it is their primary qualities that have contributed to their ability to purify their environment.
1. Why does the author think we are in greater need of “the green” in our homes?| A．To bring our long-dead gardens back to life. |
| B．To get rid of harmful chemicals trapped there. |
| C．To make us feel calmer and less worried. |
| D．To serve as decorations as well as refresh us. |
| A．The source of these chemicals released in our homes hasn’t been identified. |
| B．The chemicals can be removed immediately the two plants are put into use. |
| C．People tend to underestimate the effects of the chemical in the closed-in places. |
| D．People usually buy household products without referring to the ingredients on them. |
| A．the ability to absorb chemicals and live long |
| B．their adaptability to indoor environment |
| C．the fast growth and attractiveness of their leaves |
| D．the release of their moisture and fumes |
| A．Research in the New Millennium |
| B．Common Houseplants May Purify Your Home |
| C．Hidden Dangers in Your Home |
| D．NASA Experiment Finds the Cure |
