Despite the bad reputation of sharks, they are crucial to the health of the marine ecosystem and can even help fight climate change.
In the shallows of Shaik Bay, Western Australia, seagrass is food for the sea cows, which can weigh as much as 500 kg and eat roughly 40 kg of seagrass a day. Sea cows are a rich source of food for tiger sharks. By keeping the sea cow population controlled, tiger sharks here help the seagrass grow sustainably. A booming seagrass meadow stores twice as much CO₂ per square mile as forests typically do on land.
But tiger shark numbers are declining. Off Australia’s northeast coast of Queensland, tiger sharks are estimated to have fallen by at least 71 percent, largely due to overfishing. A reduction in tiger sharks means more seagrass consumed by herbivores (食草动物) and less carbon stored in sea vegetation. This raised the question: What if they were absent from the Shark Bay — would the seagrass-dominated ecosystem survive?
To find out, researcher led by Rob Nowicki of Florida International University, spent time in Eastern Australia, where shark numbers were lower and sea cows ate seagrass largely undisturbed. “When uncontrolled, sea cows can rapidly destroy wide areas of seagrass.” said Nowicki.
Those findings emphasized that tiger sharks were playing an important role in preventing the reduction of seagrass in Shark Bay. If their populations continue to decline, the resilience of carbon-rich ocean ecosystems will likely decrease.
When it comes to stimulating shark numbers, there have been movements toward more sustainable fishing, but a large percentage of the industry have not changed their methods, which is a reason why the population of many marine top predators (捕食者) continues to decline.
Aside from supporting sustainable fishing, Nowicki said the only way to truly protect marine life is to reduce our global greenhouse gas emissions. “Ultimately, if we are going to protect our ecosystems in the centuries to come, we are going to need to solve climate change while undertaking species protection at the same time.”
1. Why are tiger sharks vital to the marine ecosystem?| A．They feed on various sea animals. | B．They can store large amounts of CO₂. |
| C．They can prevent the loss of seagrass. | D．They influence marine species’ health |
| A．Remark. | B．Recovery. | C．Bother. | D．Accident. |
| A．Unsustainable fishing. | B．Lack of protection. |
| C．Climate change. | D．Loss of seagrass. |
| A．To tell the number of tiger sharks is decreasing. |
| B．To show climate change causes the loss of seagrass. |
| C．To tell environmental protection is at the top of the agenda. |
| D．To show tiger sharks are vital to the health of the marine ecosystem. |
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【推荐1】A ten-year-old sperm whale(抹香鲸）was found dead on a beach in Scotland.A necropsy(尸检）revealed that nearly 100 kilograms of plastic and other trash had formed clumps(硬块）in its digestive system.The tragedy quickly made headlines.Why would a top predator in the ocean eat gloves,rope,and plastic cups?
Conventional wisdom suggests that marine animals eat plastic because it is there and they don't know any better.It is true that plastic may smell like food to some of them.But that doesn't explain why only certain types of whales-deep-diving toothed whales,such as sperm whales and pilot whales-turn up dead on beaches with stomachs full of plastic.
It's possible,says Savoca,that plastic trash sounds like food to toothed whales.These species
hunt deep in the ocean,sometimes nearly 500 meters below the surface,where it's pitch black(漆黑）。They use echolocation(回声定位）to hunt for food,typically squid(乌贼）。
By contrast,baleen whales(须鲸），including humpbacks and blue whales,have natural filters(过滤器）for their food.Baleen,the brush-like filter-feeding system they have in place of teeth,as well as their narrow throats,keeping them from swallowing anything much larger than the krill(磷虾群）that forms the basis of their diet.That could help explain why baleen whales are not ending up with plastic filled stomachs.
Fifty years ago,there was almost no plastic in the ocean.The lifespan of a large whale can be
twice that long.In the lifetime of a single whale,we went from an ocean with no plastic to hundreds of thousands of tons of it.Plastic comes on top of other factors affecting life in the ocean-climate change,overfishing,shipping traffic,and noise pollution."it's a real shame because their lives are challenging enough even without the additional pressure we put onto them,"says Savoca.
1. What does Paragraph 2 mainly talk about?
| A．That plastic smells like food to toothed whales. |
| B．That marine animals started to eat plastic decades ago. |
| C．That a number of toothed whales are found dead on beaches every year. |
| D．That conventional wisdom about why marine animals eat plastic doesn't apply to all whales. |
| A．They don't feed on krill. |
| B．They live in the dark depths of the ocean. |
| C．They are not born with brush-like filter-feeding systems. |
| D．They don't determine the location of their food with their eyes. |
| A．Whales have a longer lifespan than humans. |
| B．Plastic has a negative effect on climate change. |
| C．Great changes have taken place in the ocean in the past 50 years. |
| D．Plastic pollution has worsened already serious issues affecting marine life. |
| A．Different diets,different fates |
| B．Silent killers in the ocean |
| C．Plastic trash in-the ocean |
| D．Saving whales |
【推荐2】After years of heated debate, gray wolves were reintroduced to Yellowstone National Park. Fourteen wolves were caught in Canada and transported to the park. By last year, the Yellowstone wolf population had grown to more than 170 wolves.
Gray wolves once were seen here and there in the Yellowstone area and much of the continental United States, but they were gradually displaced by human development. By the 1920s, wolves had practically disappeared from the Yellowstone area. They went farther north into the deep forests of Canada, where there were fewer humans around.
The disappearance of the wolves had many unexpected results. Deer and elk populations — major food sources (来源) for the wolf — grew rapidly. These animals consumed large amounts of vegetation (植被), which reduced plant diversity in the park. In the absence of wolves, coyote populations also grew quickly. The coyotes killed a large percentage of the park’s red foxes, and completely drove away the park’s beavers.
As early as 1966, biologists asked the government to consider reintroducing wolves to Yellowstone Park. They hoped that wolves would be able to control the elk and coyote problems. Many farmers opposed the plan because they feared that wolves would kill their farm animals or pets.
The government spent nearly 30 years coming up with a plan to reintroduce the wolvers. The U.S. Fish and Wildlife Service carefully monitors and manages the wolf packs in Yellowstone. Today, the debate continues over how well the gray wolf is fitting in at Yellowstone. Elk, deer, and coyote populations are down, while beavers and red foxes have made a comeback. The Yellowstone wolf project has been a valuable experiment to help biologists decide whether to reintroduce wolves to other parts of the country as well.
1. What is the text mainly about?| A．Wildlife research in the United States. |
| B．Plant diversity in the Yellowstone area. |
| C．The conflict between farmers and gray wolves. |
| D．The reintroduction of wolves to Yellowstone Park. |
| A．Damage to local ecology. |
| B．Preservation of vegetation. |
| C．A decline in the park’s income. |
| D．An increase in the variety of animals. |
| A．Doubtful. | B．Uncaring. | C．Positive. | D．Disapproving. |
【推荐3】The hemlock(铁杉) trees along the Wappinger Creek, New York, look healthy. However, scientist Gary Lovett says the white balls which provide protection for the bugs are created by a tiny insect. It’s hard to believe the tiny bug could kill a tree. However, trees can end up with millions and millions of the pests. When there are that many, it ends up killing the tree.
The bug from East Asia is slowly killing trees across the USA. The trouble－making bug is just one of many invasive(入侵的) pests that have slipped into the United States. They can hurt other living things in their new home.
Many invasive pests arrive on wooden pallets piled inside shipping containers. They support and separate goods, and keep them from sliding around. Invasive pests often tunnel into the pallets. How can we stop pests from riding on pallets? Lovett says new rules are needed. The companies that make pallets don’t want more rules. Congress has added an amendment(修正案) in the 2018 Farm Bill to try and prevent this problem. However, Lovett is not hopeful it will make much of a difference. Pallets are checked by inspectors. Many are sprayed with bug－killing pesticide. “I believe in the system，” said Brent McClendon, president of The National Wooden Pallet and Container Association. He also said shipping containers are checked very carefully.
Still, each year 13 million containers are shipped to the U.S. Each is full of wooden pallets. Lovett says: “Inspectors can’t possibly check everything. All it takes are a few bad pallets; we should get rid of wooden pallets.” He believes pallets should be made of plastic or eco－composite wood. Eco－composite wood is a mix of wood fiber and plastic. Insects cannot hide into it. One problem is that these choices cost more. They may be worth the extra money, though. Invasive pests cost the U.S. $5 billion a year. Trees don’t just die in forests. They also die in cities and our yards. Then, they need to be replaced. That costs money, too.
1. All the statements are TRUE except that ________.| A．pesticide has been applied to bug－killing |
| B．invasive pests are native to Wappinger Creek |
| C．invasive pests hide in pallets used in shipping |
| D．the companies making pallets don’t want more rules |
| A．Bugs can be easily spotted by eyes. |
| B．Bugs ruin the shipping goods slowly. |
| C．Bugs won’t bother the tree if just in few numbers. |
| D．Bugs cover trees with white soft balls for protection. |
| A．Because insects mostly die in them. |
| B．Because plastic pallets are eco－friendly. |
| C．Because they are not worth extra money. |
| D．Because they are the major pest carriers. |
| A．Invasive pests are harming plants in the USA. |
| B．Effective measures have stopped the pest invasion. |
| C．Congress contributes a lot to dealing with invasive pests. |
| D．Ecosystem in the USA is poorly damaged by invasive woods. |
【推荐1】Deserts could be the best places on Earth for harvesting solar power. They are spacious, relatively flat, and never short of sunlight. So researchers imagine it might be possible to transform the world’s largest desert, the Sahara, into a large solar farm, capable of meeting four times the world’s current energy demand.
While the black surfaces of solar panels absorb most of the sunlight that reaches them, only around 15% of that incoming energy gets turned into electricity. The rest is returned to the environment as heat, affecting the climate. If these effects were only local, they might not matter in a thinly populated desert. But the area of the installations in the Sahara would be vast, covering thousands of square miles. Heat released from an area this size will be redistributed by the flow of air in the atmosphere, having regional and even global effects on the climate.
A 2018 study used a climate model to assess the effects of building massive solar farms in the Sahara. The model revealed that when the size of the solar farm reaches 20% of the total area of the Sahara, the heat released by the darker solar panels creates a big temperature difference between the land and the surrounding oceans that ultimately lowers surface air pressure and causes wet air to rise and condense (凝结) into raindrops. With more rainfall, plants grow and the desert reflects less of the sun’s energy since vegetation absorbs light better than sand and soil. With more plants present, more water is evaporated (蒸发), creating a better environment that causes vegetation to spread.
So, a large solar farm could generate enough energy and at the same time turn one of the most abominable environments on Earth into a habitable place. Sounds perfect, right? Not quite. In a recent study, we used an advanced Earth system model to closely examine how Saharan solar farms interact with the climate. It showed there could be unintended effects in remote parts of the land and ocean.
We are only beginning to understand the potential consequences of establishing massive solar farms in deserts. Solutions like this may help society reduce the use of fossil energy, but Earth system studies like ours underscore the importance of considering the numerous coupled responses of the atmosphere, oceans, and land surface when examining their benefits and risks.
1. What can be learned about solar farms?| A．They are mainly located in deserts. |
| B．They can affect the local and even global climate. |
| C．They can make the best use of incoming energy. |
| D．They satisfy the world’s current energy demand. |
| A．It might become greener. |
| B．It might reflect more sunlight. |
| C．Its surface air pressure will increase. |
| D．Its temperature difference between day and night will decrease. |
| A．Addictive. | B．Dynamic. | C．Sensitive. | D．Unpleasant. |
| A．It is an impossible task. |
| B．It will do more good than harm. |
| C．It calls for more consideration. |
| D．It might be the solution to fossil fuel pollution. |
【推荐2】Many people know that rubbish is a big problem on planet Earth. What many people don't know is that rubbish has become a problem in outer space too. Years of space exploration have left tons of “space junk” in orbit around the planet. According to BBC News，there are more than 22,000 pieces of junk in space around the earth. And these are just the items that we can see from the surface of the earth by telescopes. There are also millions of smaller pieces of junk that we can't see.
Objects，like bits of old space rockets or satellites，move around the planet at very high speeds，so fast that even a very small piece can break important satellites or become dangerous to people，particularly astronauts. If the tiniest piece of junk crashed into a spacecraft，it could damage the vehicle. That's because the faster an object moves，the greater the impact if the object collides(相撞)with something else.
To help reduce additional space junk, countries around the world have agreed to limit the time their space tools stay in orbit to 25 years. Each tool must be built to fall safely into the earth's atmosphere，or the mass of gases that surround the earth. In the upper parts of the atmosphere, it will burn up. Many scientists are also putting forward different ways to clean up space junk. In England a metal tool is being tested that can be fired into space rubbish，catch the rubbish，and then pull the rubbish into the earth's atmosphere to burn up. The Germans have been planning a space project with robots that would collect pieces of space rubbish and bring them back to Earth so that they can be safely destroyed.
The problem of space junk is very challenging，and it's quite urgent as well. One reason why it's urgent is that countries are sending more and more objects into space. Many of these objects are tools that help people use their cell phones or computers. The time to act is now. As we go farther in time we will need to remove more and more fragments(碎片).
1. What can we know from the first paragraph?| A．There are 22,000 pieces of space junk around the earth. |
| B．BBC News found the pieces of space junk by telescopes. |
| C．There are millions of tiny pieces of space junk around the earth. |
| D．Space junk in orbit around the planet was left by space exploration. |
| A．To help reduce additional space junk. |
| B．To help space tools fall safely into the earth. |
| C．To help burn up space junk in the earth's atmosphere. |
| D．To help collect space junk and bring them back to Earth. |
| A．Ways to clean up space junk. |
| B．Ways to avoid the damage of space junk. |
| C．Rubbish is a big problem on planet Earth. |
| D．Rubbish has become a problem in outer space. |
| A．Health. | B．Education. | C．Environment. | D．Entertainment. |
【推荐3】Reducing food waste is easy — just ask the students at a school in Wood bridge, America, who have become experts at sorting their lunchtime trash (垃圾). Since the fall of 2019, they have actively participated in a successful food-waste diversion program that not only saves money but also contributes to reducing the amount of trash that heads to landfills.
Actually, this program plays a crucial role in facing up to the challenges of climate change. By reducing food waste,the school minimizes the amount of trash sent to landfills, thereby reducing harmful methane emissions (沼气排放). The school’s program is making a significant impact. Each month, it moves over 1,300 pounds of food waste, resulting in an estimated reduction of 772 pounds in CO, emissions and the production of 180 kilowatt-hours of energy, according to Blue Earth Compost in America.
At school, when students are done eating lunch, they head to an appointed section — a row of desks, garbage cans and containers — where they sort their trash. Leftover liquids, such as juice or milk,are emptied into a big basin on the floor. The juice containers and plastic water bottles are placed into another container to recycle. Additionally, prepackaged, unopened snacks such as bags of carrots as well as produce such as apples and bananas are “rescued” and placed into a big basket with a handwritten “Donations” sign taped to it to send to the town’s senior center.
The benefits extend beyond environmental awareness. The program reduces trash-carrying costs as less weight goes into the trash bins,making it easier for cleaners to manage. The students also find this planet-friendly practice enjoyable and meaningful, considering it a small game that contributes to a bigger cause. This initiative proves that collective efforts, even on a smaller scale, can lead to significant changes, not only in waste reduction but also in educating a generation committed to preserving our planet.
1. What does the food-waste reduction program focus on at the school in Wood bridge?| A．Saving school food. |
| B．Donating unopened snacks. |
| C．Fertilizing the school’s garden. |
| D．Minimizing harmful gases emissions. |
| A．It leads to food cost reducing. |
| B．It helps with energy production. |
| C．It improves waste management. |
| D．It addresses climate change effectively. |
| A．Saved. | B．Frozen. | C．Abandoned. | D．Repurposed |
| A．It is costly but highly effective. |
| B．It is easy to perform and cost-saving. |
| C．It is expensive and difficult to apply. |
| D．It is only accessible in large companies. |
【推荐1】The Rise of the Grown-Up Gap Year
It was 2012,Tim Potter, who was in public relations, had just finished working on the London Olympics alongside his partner.A career break to go travelling — or a “grown-up gap year”— seemed like a natural thing to both of them.
The couple spent four months traveling around Asia. Next, they flew to Mexico via Canada, worked their way down through Central America, and spent a month in both Colombia and Brazil.
But is Potter’s experience common or did he get lucky? Some people assume taking a career break will automatically be off-putting to potential employers, but according to Emily Bain, managing director of secretarial recruitment agency Bain and Gray, it can actually be quite the opposite.
“As an employer, I see it as a positive,” she says.
Tim Fryer, U.K. manager at STA Travel, says grown-up gap years can have a positive effect on your career. “Taking a break gives travelers time to refocus on work as well as the space to reflect on what exactly it is they want to do,” he explains.
Let’s not get ahead of ourselves, though. Emily Bain admits that some employers’ instinct is to turn their noses up at someone who’s had a break. However, she says, the duty is on the traveler to sell their experience as something that will benefit their future employer. “You have to explain the whole picture,” she says. “Making your CV (简历) gap accountable actually brings your profile to life.” So, don’t hide it — make a big deal of it.
Bain holds that although gap years are acceptable, it is still important to learn some kind of skill regardless of whatever else you may be doing during this time.
| A．These people are often at a turning point in their careers or lives. |
| B．The desire to go travelling is by no means all work-related, though. |
| C．The most obvious skill to take from travel, of course, is a language. |
| D．Taking a gap year when you’re older means that you have different things to consider. |
| E．Not in any way did the lack of work affect his prospects. |
| F．Bain goes on to say that taking a grown-up gap year is more common than you’d think. |
【推荐2】Scientists at the UCL Institute for Neurology have developed new tools, based on AI language models, that can characterize subtle signatures in the speech of patients diagnosed with schizophrenia (精神分裂症). The research, published in PNAS, aims to understand how the automated analysis of language could help doctors and scientists diagnose and assess psychiatric (病) conditions.
Currently, psychiatric diagnosis is based almost entirely on talking with patients and those close to them, with only a minimal role for tests such as blood tests and brain scans. However, this lack of precision prevents a richer understanding of the causes of mental illness and the monitoring of treatment.
The researchers asked 26 participants with schizophrenia and 26 control participants to complete two verbal fluency tasks, where they were asked to name as many words as they could either belonging to the category “animals” or starting with the letter “p” in five minutes. To analyze the answers given by participants, the team used an AI language model to represent the meaning of words in a similar way to humans. They tested whether the words people naturally recalled could be predicted by the AI model, and whether this predictability was reduced in patients with schizophrenia.
They found that the answers given by control participants were indeed more predictable by the AI model than those generated by people with schizophrenia, and that this difference was largest in patients with more severe symptoms. The researchers think that this difference might have to do with the way the brain learns relationships between memories and ideas, and stores this information in so called “cognitive maps”.
The team now plan to use this technology in a larger sample of patients, across more diverse speech setting, to test whether it might prove useful in the clinic. Lead author, Dr. Matthew Nour, said: “There is enormous interest in using AI language models in medicine. If these tools prove safe, I expect they will begin to be used in the clinic within the next decade.”
1. What is the disadvantage of current psychiatric diagnosis?| A．It is greatly related to blood tests. | B．It mostly relies on talking with patients. |
| C．It refers to the words of patients’ family. | D．It can’t comprehend schizophrenia deeply. |
| A．The process of the research. | B．The tasks of the participants. |
| C．The performance of researchers. | D．The predictability of AI language models |
| A．Unclear. | B．Positive. | C．Doubtful. | D．Negative. |
| A．AI language new tools used in the clinic. | B．AI language tools developed by scientists. |
| C．AI language models treating schizophrenia. | D．AI language models diagnosing schizophrenia. |
Wherever you are in Britain, there’s likely to be a theme park within one or two hours’ drive, bus ride or train journey. Several theme parks even have accommodation(膳宿) so you can stay for a day or two if you want to make a trip into a short holiday.
Prices for UK theme parks vary considerably; some have an entrance price which allows you to go on all the rides, while in others you have to pay for every ride individually. It can also make a difference whether you go during peak time or not. For example, tickets always cost more during school holidays and weekends than they do during the weekdays.
Theme parks always get very busy during the summer months, so if you don’t like crowds, it’s usually a good idea to go earlier or later in the year!
If you’re thinking of visiting a UK theme park, it’s worth having a look for special offers on tickets. Products such as chocolate bars and cereals sometimes have “buy one get one free” offers on theme park tickets, so keep a look out in shops and supermarkets.
1. This passage mainly talks about all the following EXCEPT .
| A．things to do | B．prices for theme parks |
| C．rules to obey | D．special offers |
| A．have lunch | B．stay for the night |
| C．enjoy special offers | D．have a skiing |
| A．have to spend more | B．save some money |
| C．get something free | D．have a good time |
| A．Avoid the busiest months. |
| B．Go earlier or later in the daytime. |
| C．Choose one with few visitors. |
| D．Go there when no one is in it. |
| A．What to Do in the Theme Park |
| B．Theme Parks in the UK |
| C．Visiting the Theme Park |
| D．Introduction to Famous Theme Parks |
