Plastic-Eating Worms
Humans produce more than 300 million tons of plastic every year. Almost half of that winds up in landfills (垃圾填埋场), and up to 12 million tons pollute the oceans. So far there is no effective way to get rid of it, but a new study suggests an answer may lie in the stomachs of some hungry worms.
Researchers in Spain and England recently found that the worms of the greater wax moth can break down polyethylene, which accounts for 40% of plastics. The team left 100 wax worms on a commercial polyethylene shopping bag for 12 hours, and the worms consumed and broke down about 92 milligrams, or almost 3% of it. To confirm that the worms’ chewing alone was not responsible for the polyethylene breakdown, the researchers made some worms into paste (糊状物) and applied it to plastic films. 14 hours later the films had lost 13% of their mass — apparently broken down by enzymes (酶) from the worms’ stomachs. Their findings were published in Current Biology in 2017.
Federica Bertocchini, co-author of the study, says the worms’ ability to break down their everyday food — beeswax — also allows them to break down plastic. “Wax is a complex mixture, but the basic bond in polyethylene, the carbon-carbon bond, is there as well,” she explains, “The wax worm evolved a method or system to break this bond.”
Jennifer DeBruyn, a microbiologist at the University of Tennessee, who was not involved in the study, says it is not surprising that such worms can break down polyethylene. But compared with previous studies, she finds the speed of breaking down in this one exciting. The next step, DeBruyn says, will be to identify the cause of the breakdown. Is it an enzyme produced by the worm itself or by its gut microbes (肠道微生物)?
Bertocchini agrees and hopes her team’s findings might one day help employ the enzyme to break down plastics in landfills. But she expects using the chemical in some kind of industrial process — not simply “millions of worms thrown on top of the plastic.”
It can be inferred from the last paragraph that the chemical might ________.
A.help to raise worms |
B.help make plastic bags |
C.be used to clean the oceans |
D.be produced in factories in future |
相似题推荐
设计关于野生动物保护的书签
Design a series of bookmarks on wildlife protection
【推荐2】Five years ago, French navy officer Jérôme Chardon was listening to a radio program about the journey of the bar-tailed godwit, a bird that migrates 14,000 kilometers between New Zealand and Alaska. Chardon understood how treacherous the journey would be, as heavy storms frequently hit Pacific island communities. Yet, somehow, bar-tailed godwits routinely pass through the area uninjured. Chardon wondered whether learning how birds traveled could help coastal communities avoid natural disasters.
Which of the following best explains the word “treacherous” underlined in paragraph 1?
A.Strange. | B.Boring. | C.Frequent. | D.Dangerous. |
Why did the author decide to send Spot and Stripe back to the zoo?
A.They frightened the children. | B.They became difficult to contain. |
C.They annoyed the neighbours. | D.They started fighting each other. |
【推荐1】Vast underwater meadows (草甸) of gently waving sea grass cover hundreds of miles up and down the West Coast. These blue-green fields perform a variety of important services. They protect the shoreline from erosion, clear pollutants from the water and provide habitats for all kinds of marine animals.
New research suggests sea grass meadows may also mitigate a serious consequence of greenhouse gas emissions: the steady acidification of ocean waters. The study published in the journal Global Change Biology finds that sea grass forests can raise pH levels in coastal waters. As they perform photosynthesis (光合作用), they remove carbon dioxide from the water, counteracting the acidifying effect of the gas.
“I think we are all very excited about it,” said lead study author Aurora Ricart, a scientist at the Bigelow Laboratory for Marine Sciences.
Ocean acidification is a side effect of rising carbon dioxide levels in the atmosphere. Some of this CO2 dissolves out of the air and into the sea, causing a chemical reaction that lowers the water’s pH. Scientists sometimes refer to it as global warming’s “evil twin”—an invisible companion to climate change.
Ocean acidification can have harmful effects on marine organisms like shellfish and coral by preventing them from properly forming the hard shells they need to survive. It’s a threat both to natural ecosystems and to shellfish fisheries around the world. The study presents a natural way to address the problem.
Researchers analyzed six years of data from sea grass meadows spanning more than 600 miles off the California coastline. It focused on the common eelgrass, one of the most widespread sea grass species on the West Coast. The authors claim it’s the largest, most comprehensive study of its kind.
According to the study, sea grass ecosystems can raise pH levels by more than 0.1 unit, equivalent to about a 30% decrease in acidity. The effect isn’t constant. It comes in waves and is influenced by temperature, daylight, ocean currents and other factors that affect water chemistry and sea grass photosynthesis rates. But the tempering influence on acidification can be lasting, sometimes persisting for up to three weeks at a time. The study also shows that pH is higher in sea grass ecosystems, compared to nearby areas with no sea grass, about 65% of the time.
The study didn’t investigate the effects of higher pH on marine organisms — that’s a question for future research. But there’s reason to believe these meadows may have a positive influence on shellfish and other ocean animals.
Why does the author write this passage?
A.To illustrate the serious situation of climate change. |
B.To present the living conditions of the underwater meadows. |
C.To emphasize the importance of research on marine pollution. |
D.To introduce a natural way to solve the problem of ocean acidification. |
【推荐2】Live with roommates? Have friends and family around you? Chances are that if you’re looking to live a more sustainable lifestyle, not everyone around you will be ready to jump on that bandwagon.
I experienced this when I started switching to a zero-waste lifestyle five years ago, as I was living with my parents, and I continue to experience this with my husband, as he is not completely zero waste like me. I’ve learned a few things along the way though, which I hope you’ll find encouraging if you’re doing your best to figure out how you can make the change in a not-always-supportive household.
Zero waste was a radical lifestyle movement a few years back. I remember showing my parents a video of Bea Johnson, sharing how cool I thought it would be to buy groceries with jars, and have so little trash! A few days later, I came back with my first jars of zero waste groceries, and my dad commented on how silly it was for me to carry jars everywhere. It came off as a bit discouraging.
Yet as the months of reducing waste continued, I did what I could that was within my own reach. I had my own bedroom, so I worked on removing things I didn’t need. Since I had my own toiletries (洗漱用品), I was able to start personalizing my routine to be more sustainable. I also offered to cook every so often, so I portioned out a bit of the cupboard for my own zero waste groceries. Perhaps your household won’t entirely make the switch, but you may have some control over your own personal spaces to make the changes you desire.
As you make your lifestyle changes, you may find yourself wanting to speak up for yourself if others comment on what you’re doing, which can turn itself into a whole household debate. If you have individuals who are not on board, your words probably won’t do much and can often leave you feeling more discouraged.
So here is my advice: Lead by action.
1. What was the attitude of the author’s father toward buying groceries with jars?A.He disapproved of it. | B.He was favorable to it. |
C.He was tolerant of it. | D.He didn’t care about it. |
A.She is quite good at cooking. | B.She respects others’ privacy. |
C.She enjoys being a housewife. | D.She is a determined person. |
【推荐3】Vast underwater meadows (草甸) of gently waving sea grass cover hundreds of miles up and down the West Coast. These blue-green fields perform a variety of important services. They protect the shoreline from erosion, clear pollutants from the water and provide habitats for all kinds of marine animals.
New research suggests sea grass meadows may also mitigate a serious consequence of greenhouse gas emissions: the steady acidification of ocean waters. The study published in the journal Global Change Biology finds that sea grass forests can raise pH levels in coastal waters. As they perform photosynthesis (光合作用), they remove carbon dioxide from the water, counteracting the acidifying effect of the gas.
“I think we are all very excited about it,” said lead study author Aurora Ricart, a scientist at the Bigelow Laboratory for Marine Sciences.
Ocean acidification is a side effect of rising carbon dioxide levels in the atmosphere. Some of this CO2 dissolves out of the air and into the sea, causing a chemical reaction that lowers the water’s pH. Scientists sometimes refer to it as global warming’s “evil twin”—an invisible companion to climate change.
Ocean acidification can have harmful effects on marine organisms like shellfish and coral by preventing them from properly forming the hard shells they need to survive. It’s a threat both to natural ecosystems and to shellfish fisheries around the world. The study presents a natural way to address the problem.
Researchers analyzed six years of data from sea grass meadows spanning more than 600 miles off the California coastline. It focused on the common eelgrass, one of the most widespread sea grass species on the West Coast. The authors claim it’s the largest, most comprehensive study of its kind.
According to the study, sea grass ecosystems can raise pH levels by more than 0.1 unit, equivalent to about a 30% decrease in acidity. The effect isn’t constant. It comes in waves and is influenced by temperature, daylight, ocean currents and other factors that affect water chemistry and sea grass photosynthesis rates. But the tempering influence on acidification can be lasting, sometimes persisting for up to three weeks at a time. The study also shows that pH is higher in sea grass ecosystems, compared to nearby areas with no sea grass, about 65% of the time.
The study didn’t investigate the effects of higher pH on marine organisms — that’s a question for future research. But there’s reason to believe these meadows may have a positive influence on shellfish and other ocean animals.
What can we learn from this passage?
A.Sea grass forests can lower pH levels of coastal waters. |
B.Shellfish and corals are not affected by ocean acidification. |
C.Sea grass meadows can help remove pollutants from the sea water. |
D.The effects of higher pH on marine organisms were investigated in this study. |
【推荐1】Despite being connected online, no matter what state you’re from, each city still retains its own language and slang. At my public high school in Los Angeles, we had our own secret language. A party was a “yart”. A beer was a “brewsky”. If I tried to use these words in front of anyone that didn’t live in Los Angeles, they would have no idea what was going on. When I came to college and used these words around my roommate from the East Coast, she would look at me with a blank stare.
Teenagers are often blamed for pulling apart standard linguistic patterns. The way my parents used to talk isn’t the same way that teenagers talk now. But it reflects the dynamic nature of language, which evolves over time due to various influences, including generational shifts and technological advancements. Teenagers, at an age when they are actively exploring their identity and seeking to differentiate themselves from previous generations, often play a significant role in this evolution.
It’s interesting to note that people around the world all have different terms for everyday things. Last year, I came across a British show called Love Island, which is a reality show that mixes people from different parts of the U. K. in a “villa”(another word Americans don’t typically say) for about eight weeks. As a bystander, the way they talked felt so elegant and fun, but to them, it was just normal.
Whether the way we talk is regional or from online, the soul of communication lies in its power to connect people, foster understanding, and facilitate interactions that shape our personal and social lives. I have often found it’s the way we connect with the people we live around.
What is mainly talked about in the last paragraph?A.The means of communication. | B.The nature of communication. |
C.The elements of communication. | D.The process of communication. |
【推荐2】Good Morning Britain’s Susanna Reid is used to grilling guests on the sofa every morning, but she is cooking up a storm in her latest role — showing families how to prepare delicious and nutritious meals on a tight budget.
In Save Money: Good Food, she visits a different home each week and with the help of chef Matt Tebbutt offers top tips on how to reduce food waste, while preparing recipes for under £5 per family a day. And the Good Morning Britain presenter says she’s been able to put a lot of what she’s leant into practice in her own home, preparing meals for sons, Sam,14, Finn,13, and Jack, 11.
“We love Mexican churros, so I buy them on my phone from my local Mexican takeaway restaurant,” she explains. “I pay £5 for a portion (一份), but Matt makes them for 26p a portion, because they are flour, water, sugar and oil. Everybody can buy takeaway food, but sometimes we’re not aware how cheaply we can make this food ourselves.”
The eight-part series (系列节自), Save Money: Good Food, follows in the footsteps of ITV’s Save Money: Good Health, which gave viewers advice on how to get value from the vast range of health products on the market.
With food our biggest weekly household expense, Susanna and Matt spend time with a different family each week. In tonight’s Easter special they come to the aid of a family in need of some delicious inspiration on a budget. The team transforms the family’s long weekend of celebration with less expensive but still tasty recipes.
1. What do we know about Susanna Reid?A.She enjoys embarrassing her guests. |
B.She has started a new programme. |
C.She dislikes working early in the morning. |
D.She has had a light budget for her family. |
A.He buys cooking materials for her. |
B.He prepares food for her kids. |
C.He assists her in cooking matters. |
D.He invites guest families for her. |
【推荐3】Even before they became fashionable companions for humans, Asia’s wild otters faced plenty of threats. Their habitats are disappearing. They have long been hunted for their coats, or killed by farmers who wish to prevent them consuming fishes. The pet trade, which began picking up in the early 2000s but appeared to speed up a few years ago, has made things worse. The numbers of wild Asian small-clawed otters and smooth-coated otters, two species that are in highest demand, have declined by at least 30% in the three decades to 2019.
The international agreement that governs trade in wildlife, known as CITES, now prohibits cross-border trade in these species. But laws banning ownership are often poorly implemented, as in Thailand, or full of holes, as in Indonesia. And the otter-keeping craze has been dramatically improved by the internet, says Vincent Nijman of Oxford Brookes University.
The purpose of the writing is to ________.
A.advertise for a photo-sharing app |
B.introduce the popularity of pet otters |
C.discourage the illegal otter pet trade |
D.describe the characteristics of otters |
【推荐1】He was amazed at the results. The plants and animals in the eco-machine took the sludge as food and began to eat it! Within weeks, it had all been digested, and all that was left was pure water.
Over the years, John has taken on many big jobs. He developed a greenhouse — like facility that treated sewage (污水) from 1,600 homes in South Burlington. He also designed an eco-machine to clean canal water in Fuzhou, a city in southeast China.
“Ecological design” is the name John gives to what he does. “Life on Earth is kind of a box of spare parts for the inventor,” he says. “You put organisms in new relationships and observe what’s happening. Then you let these new systems develop their own ways to self-repair.”
1. What is the author’s purpose in mentioning Fuzhou?A.To review John’s research plans. |
B.To show an application of John’s idea. |
C.To compare John’s different jobs. |
D.To erase doubts about John’s invention. |
A.Nature can repair itself. |
B.Organisms need water to survive. |
C.Life on Earth is diverse. |
D.Most tiny creatures live in groups. |
【推荐2】We may think we’re a culture that gets rid of our worn technology at the first sight of something shiny and new, but a new study shows that we keep using our old devices (装置) well after they go out of style. That’s bad news for the environment — and our wallets — as these outdated devices consume much more energy than the newer ones that do the same things.
What does the author think of new devices?
A.They are environmentfriendly. |
B.They are no better than the old. |
C.They cost more to use at home. |
D.They go out of style quickly. |
【推荐3】Dr Zhang admits that film therapy does not work for everyone, but says he has used it successfully with about a third of his clients. “Through the films’ characters, plots and even music, it allows people to face their problems.” He said that Falling Down, in which Michael Douglas plays the part of an unemployed man who is so depressed that he uses violence, was an example of the dangerous results of not letting anger go. “I used this film with a patient who was very upset because he was holding back a lot of the anger he felt towards people who had hurt him,” said Dr Zhang. “We talked about Michael Douglas’s character and the disastrous path he takes, and my patient then realized that he needed to let go of his feelings more regularly so as not to burst out like a time bomb.”
What can we learn about Dr. Zhang?
A.He used to be an actor. |
B.He likes to review different films. |
C.He favors the film therapy. |
D.He is good at sharing his feelings. |