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Most air conditioners and fridges rely on contracting and expanding a liquid to either absorb or release large quantities of heat. While these systems are relatively cheap and simple to produce, they aren't very efficient and require lots of energy. Besides, many of the coolants used are environmentally harmful.

Now, Emmanuel Defay at the Luxembourg Institute of Science and Technology and his colleagues have developed a coolant-free refrigeration device made from the metals lead, scandium (钪) and tantalum (钼). It can reach maximum efficiencies of more than 60%, almost double that of typical single-room air conditioning units. The technology is based on a principle called electrocaloric cooling, in which an electric field applied across a material changes the direction of electric charges, causing a temporary increase in temperature and a succeeding decrease when the electric field is removed.

To make their cooling system, Defay and his colleagues piled up eight strips of the material known as lead scandium tantalate, which is electrocaloric, on top of one another and dipped them in a heat-carrying liquid, silicone oil. When an electric field is switched on and the strips heat up, the liquid moves to the right, and when it cools down, it moves to the left, creating permanent regions of hot and cold of about 20℃difference. These regions can be used as hot and cold reservoirs from which the oil can be circulated through pipes to cool or heat rooms or objects as desired.

"Although the efficiency of the device is theoretically 67%, the efficiency of the current design is around 12%. This could be improved if a better conductor of heat than the lead scandium tantalate were found," said Defay.

"A highest performance has been achieved by combining known elements," said NeilMathur at the University of Cambridge. However, he added, the team only looked at the cooling power of the pile of metal strips themselves, while it would be interesting to see how the entire device performs together.

Children's museums become an essential part of our play menu. Here are 4 famous muse-ums for families.

KidsQuest Children's Museum

It features huge windows, beautifully designed exhibits and an adventurous, two-story rope ladders in the opening gallery. Kids of all ages will love building with real tools in the re-cycled room, running the cash register, doing physics experiments on water in the Water Lab and much more. Reservations are required. You can make them online.

Imagine Children's Museum

Imagine Children's Museum's new 33,000-square-foot expansion doubles the museum's previous play space and its shows. At over 60,000 square feet, its current area is much bigger than other local children's museums (which average around 10,000-20,000 square feet). Visitors can spend hours in the museum.

Children's Museum of Tacoma

At 10,000 square feet in size, the Children's Museum of Tacoma has a huge draw. Since it opened about a decade ago, it has offered pay-as-you-will admission and has no plans to change that anytime soon. This means that you can stop off for an hour, without worrying about whether you've gotten your money's worth.

Seattle Children's Museum

This kid-favorite spot is located on the lower level of the Seattle Center Armory building. Long-time museum lovers will notice a new exhibit, a post office where kids can weigh packages and slide behind the driver's seat to make pretend deliveries.

1.象征物名称；

2.象征物特色；

3.推荐理由。

注意：

1.词数 100左右；

2.可以适当增加细节，以使行文连贯。

增加： 在缺词处加一个漏字符号( ). 并在其下面写出该加的词。

删除： 把多余的词用(＼)划掉。

修改： 在错的词下画一横线, 并在该词下面写出修改后的词。

注意：

1. 每处错误及其修改均仅限一词; 

2. 只允许修改10处, 多者(从第11处起)不计分。

Recently our class have had a debate. Its topic focuses on if it is necessary to use high technology to beautify the Palace Museum. As for this, different students hold different opinion. 

Some are in favor of the creative idea because of the use of high technology can add beauty to the Palace Museum, thus make it more attractive to visitors. Therefore, those who are against the idea thinks that this technology will destroy the original appearance of the Palace Museum. More important, it is extremely essential to respect the history and tradition. 

From me point of view, other measures can be taken attract more visitors. And it's our duty to provide the complete and genuine ancient palace for the world.

A flood of tourists, some from overseas, have come to enjoy the unique cultural and natural beauties of the Tibet autonomous region,  has witnessed a travel boom recently.

Of the total tourists received, 30,455 were inbound visitors —travelers from overseas — increase of 494 percent year-on-year, while more than 24.21 million were domestic visitors, a 4l percent year-on-year increase.

" impressed me the most was the magnificent Potala Palace and strong (religion) culture in Lhasa.I feel something different from other (place) I visited before," said Hu Wei, a tourist from Sichuan province.

The Chinese online travel agency Ctrip Group reported that travel order volume, including transportation and hotel bookings, for destinations in Tibet during the first half of the year increased  103 percent (compare) with the same period in 2019. The figure reflects a continuous warming trend of tourism in the region.

"It is harder (get) tickets to some hot tourism spots, such as the Potala Palace, as the number of tourists (increase) significantly recently," said Chodar, a tour guide in Lhasa. "I see large numbers of tourists lined up at the entrance of the palace every day. Visitors have to make a (reserve) at least 10 days in advance."

In 2013, Alie Ward's life was falling apart. In a matter of months, her relationship with her partner ended, her dad was 1 with a rare form of cancer, and she was also feeling a gap between the career she had chosen and the person she wanted to be.

To distract herself from her 2 , Ward liked to find and take 3 of bugs which she has loved since she was a little kid. Sometimes, if she found a beetle or a bee that she particularly liked, she'd 4 it on Facebook. Those posts attracted the 5 of a woman named Lila Higgins, who studies 6 at the local natural history museum. After seeing Ward's pictures, Higgins 7 to Ward and invited her to go on a tour of the museum.

At that time Ward was emotionally fragile, and meeting someone new in that state made her nervous and teary. However, her passion for bugs outweighed her anxiety. 

Upon Ward's arrival at the museum, Higgins warmly 8 her and handed her a lab coat. She then led Ward through various 9 . "I remember she opened up this freezer, like, ‘Come check this out,' and it was full of dead bugs," Ward recalled. "Although lifeless, these samples held significance for the natural history museum, serving as evidence to nature's diversity. I was also impressed by how 10 Higgins was, which made me feel passionate about the work for the first time in a long time," Ward continued. Noticing Ward's 11 , Higgins suggested she 12 at the museum for a few hours every week.

Despite her doubts, Ward decided to 13 Every Wednesday, she'd arrive at the museum. And with each volunteer 14 , she felt a little bit better. "It gave me this sense of 15 . It helped me reconnect with my love of 16 and nature that I'd always had," Ward said.

Soon, Ward 17 her job and started working in science media. She now is the creator and host of a podcast called Ologies. Ward had Higgins on the show as her first 18 . "Sometimes I wonder what would have happened if I hadn't taken her up on her 19 . What would my life have been like? It's not a nice thought. Who would I be? You know, Lila Higgins, in one instant, 20 my whole life," said Ward.

Before we even realize it's happening, slowly but surely, we start losing confidence in who we are, what we do, and pretty much everything we ever thought we knew. You're not alone. Below are simple steps that it offers to help you restore confidence quickly.

Figure Out the Root Cause. Knowing why you're losing confidence is key to reversing that downward spiral. Not only will it get your confidence back but also it will strengthen it in the process. So, take the time to become aware of your environment, your thoughts, your behaviors, and your relationships.

Strike a Pose. Simply put you stand straight, take up some space, put one hand on each hip, chin tilted upward, breathe in, and be present. Hold this pose for a few minutes. Our attitudes often follow our behaviors, her research suggests, meaning that assuming the body language of a powerful person can make anyone who does it feel more confident.

Losing confidence means you've given your power away. And one of the fastest ways to take back your power is to utter a tiny two-letter word: NO, Practice saying "no" at least once a day. It can be to your own judgy voices of doubt, or it can be to the external factors you've identified that have caused you to lose confidence. It, along with these other suggestions: are very powerful steps in restoring your confidence.

Losing confidence in ourselves happens.I bet if you ask the people closest to you in your life, they'll shrug and nod, letting you know that they've experienced self-doubt and a loss of confidence, too. It's part of being human and part of living this thing that we call life.

A. Just Say "No".

B. You will benefit from it in the long term.

C. They may help you find out your mistakes.

D. It's happened to me on more than one occasion.

E. It's one of the power poses suggested by social psychologist Amy Cuddy.

F. In that case, you can identify the negative influences that need to be addressed.

G. According to the online therapy platform Better Health, everyone lacks confidence occasionally.

Flip-flops (人字拖) are the most popular type of shoe in the world. They're comfortable, they're easy to wear and they're inexpensive. Unfortunately, most of them are also terrible for the environment. In Kenya, this is a huge problem, and around 90 tons of flip-flops wash up on its shores annually.

In the late 1990s, when Julie Church was working as a marine (海洋的) conservationist in Nairobi, she found an entire beach "just covered in flip-flops". Around that time, Church also noticed children making toys out of the thousands of flip-flops that had made their way to the country's beaches. She began working with the kids' mothers to encourage them to not just collect the shoes, but also turn them into artworks. The families could then sell this art at local markets, providing another means of income.

The idea took off, and in 1998, Church founded Ocean Sole as a nonprofit. This year alone, the organization has upcycled more than 750,000 flip-flops and collected more than 47,000 kilos of waste. Additionally, Ocean Sole directly impacts more than 1,000 Kenyans, many of whom work as flip-flop collectors or artists, and contributes 10% to 15% of overall income to career and educational programs for residents, as well as beach cleanup and conservation efforts.

Ocean Sole is continuously growing and looking to keep waste off Kenya's beaches and out of its water. When it comes to growing the Ocean Sole organization, Church has three "mantras (真言)": trust to trade, trade to awareness, and awareness to protection. Church would like to put together toolkits and other resources to bring this concept to other places around the world that have similar problems. Ocean Sole is also encouraging companies to use more eco-friendly materials when making flip-flops. "I think it's time for us to start looking for an alternative shoe, or an alternative material, to fit that kind of fashion need," Church has said. "Our products need to develop."

The brain of a woodpecker (啄木鸟) experiences a seemingly catastrophic impact every time its beak (喙) meets wood. "When you see these birds with hard beaks, flexible tongues and strong neck muscles in action, hitting their head against a tree quite violently, then as humans we start wondering how these birds avoid getting headaches or brain damage," says Van Wassenbergh, a researcher at the University of Antwerp in Belgium.

In the past, scientists have suggested the bird's brain is protected from the impacts, perhaps by a beak that absorbs some of the force, or something in its head that acts as a cushion (缓冲物). But Van Wassenbergh wasn't convinced. So he led a team to settle the issue using high-speed video of woodpeckers in action.The videos revealed some remarkable details. For example, "they close their eyes at the moment they impact the wood," Van Wassenbergh says, to protect their eyes from pieces of wood.

The videos also showed that woodpeckers' beaks often get stuck in the wood. But they break free almost instantly, thanks to a clever beak design that provides independent motion of the upper and lower beak.

What the videos did not show is any sign that the woodpecker's brain is somehow cushioned. "The way we see the head behaving is very rigid, like a tool hitting wood," Van Wassenbergh says. That means the organ repeatedly experiences slowdowns that would cause an injury in a human brain.

Yet the woodpecker brain is unharmed even after thousands of impacts in a single day. That is possible because a woodpecker's brain is protected—not by cushioning, but by its tiny size and weight, Van Wassenbergh says. "An animal that has a smaller size can stand higher slowdowns" he says. "That's a biomechanical law."

That idea was suggested in 2006 by Lorna Gibson, a professor at MIT. Now, it has been confirmed by Van Wassenbergh's high-speed videos.A woodpecker's brain is about 700 times smaller than a human brain. "That is why even the hardest hits we observed are not expected to cause any injury," Van Wassenbergh says.

I spent my childhood collecting and pressing four-leaf clovers（三叶草）into books at my mother's house. I started with big cloth-and-leather-bound books. When I ran out of bound volumes，I began to slip my treasures into anything I could find，such as old fiction paperbacks and cookbooks. The same is true in my house today. Shake a book，and a treasure just might fall into your hand.

A few years ago，in Nova Scotia，my husband and I pulled off the road for a picnic. The ground was thick with clovers. Some shoots had four，five，or even six leaves. I lined them up on the picnic table to admire. To me，it was simple. The differences in their shapes made them stand out，breaking the pretty pattern of the common clovers with three perfect leaves.

Two summers back，while waiting for an airport shuttle in Munich，I found a tiny four-leaf clover in a traffic circle and put it in my passport. On the way home，my husband and I were upgraded to business class. All of my friends owed it to the clover. I think it's some likely that we were upgraded because a flight was postponed，which left us trapped in two cities for several hours.

People disagree about whether the luck comes for finding or possessing a clover. Some believe that the luck is lost if the four-leaf clover is shown to somebody else，while others think that the luck doubles if it is given away. I believe that positivity is compounded by sharing. I feel lucky to find the clovers so often，but I don't think they influence my life anymore than it does to share any thing a little special with a friend or a stranger.

Winter sports are constantly evolving and new sports activities are regularly being created. This makes sure your next holiday in the snow is an unforgettable experience. 

Snow biking

The snowbike — a cross between a bicycle and skis — guarantees pure fun and a unique skiing experience for snow fans above six. Snowbikes can be used on well-cared-for slopes (斜坡) and riders navigate the slopes with the additional help of short foot skis. And it can be ridden without the rider having previous experience.

Freeriding

There is no other winter sport that gets you closer to nature. Due to the truly unaffected character of the slopes, snow and weather conditions have to be taken into special consideration when freeriding. Therefore, it is very important to be accompanied by a professional guide who knows the skiing area inside out and who is able to correctly assess the weather conditions. 

Snowshoeing

Snowshoeing is the perfect activity for those who want to explore the untouched winter landscape. The snowshoes distribute the weight of the person carrying them over a larger area so that the feet only sink lightly into the snow. Handling snowshoes is easy and does not require any previous experience: Simply fasten your snowshoes, pick up your sticks and off you go!

Snowtubing

Snowtubing is an activity for winter fans of all ages and involves sliding down a snowtubing slope in a rubber tire. Snowtubing tracks are often located close to a ski lift. This gives the tuber the opportunity to immediately go back up the mountain after the ride. The activity is the perfect and fun end to a day of skiing. 

Tyra Winters was a high school student in Texas. One day, she was marching towards her home after the school day. As she slowly made her way down the street, the 17-year-old was enthusiastically planning the coming weekend party with her best friends, thinking of all the music, laughter, and excitement.

All of a sudden, a horrific scream was heard in the street. Turning back, Winters saw a boy about two years old lying on the sidewalk. And his wild mother was begging for help. "Someone help me, someone help me". The little boy, Clarke Hornback, as his mother told, had been sucking on a piece of candy when it slid down the back of his mouth. It was stuck in his throat and blocked his windpipe (气管). Clarke's face was bright red. "There was no coughing; there was no breathing!" Clarke's mother, Nicole Hornback cried in great panic.

The crowds soon gathered around the poor boy and the mother. The boy was just gasping (喘气) for air. No one seemed to know how to help.

Except for Winters, who had always had dreams of becoming a surgeon for children! She had learned the first aid knowledge for treating choking. It was time for her to save the boy's life. Knowing that the clock was ticking, she ran to the child.

Paragraph 1:

By the time Winters got to Clarke, the boy's face had tuned purple.

Paragraph 2: 

It all happened so fast that Nicole even had no time to thank the girl.

1. 发出邀请；

2. 介绍活动；

3. 表达期待。

注意： 

1. 词数80左右；

2. 可适当增加细节，以使行文连贯。

The Columbian Exchange,  36  (name) so in 1972 by professor Alfred Crosby in the University of Texas at Austin, was the exchange of crops, animals, ideas and foods between the New World (the Americas) and the Old World (Europe, Africa and Asia) following the journeys of explorers, conquerors and traders. When  37  (return) to the Old World, they took plants  38  are native to the Americas such as com, potatoes, tomatoes, chili peppers and tobacco (烟草), along with valuable gems (宝石) and minerals. Explorers and traders in turn  39  (bring) to the New World apples, bananas, grapes, cattle, chicken and garlic.

The exchange of these foods and animals had a(n)  40 (power) impact on the eating patterns of peoples around the world. Elizabeth Lambert Ortiz wrote in her book The Food of Spain and Portugal, " 41  cannot be stressed too strongly that the importing of foods by Spain and Portugal from the Americas was  42  most significant  43  (develop) in cuisine in the 16th and 17th centuries." The impact wasn't just felt in Spain, Portugal and other European  44  (country). The New World foods also traveled with traders to Asia,  45  (actual) making the impacts truly global.

A Texas mother is helping children around the world learn a new language through her bilingual (双语的) teddy bear line. Dr. Tameka Maiden says she was trying to teach her then-1-year-old daughter, Tori, the colors when she 1  the idea for Cubby Love Bears, a line of colorful teddy bears that recite (诵读) letters, words, and numbers in English and Spanish.

"I 2 my daughter to have more exposure in the world than just English," Maiden, 38, explains. "Most kids don't learn a second 3 until they're in high school, so I was like, ‘How about I start them 4 and that way, they'll have a foundation (基础) and by the time they get 5 , it's something that they'll already have and they can expand on?"

Now 7 years old, Tori, along with hundreds of other 6 around the world, have 7 how to recite colors, letters and numbers in English and Spanish, 8 Maiden's brand.

"My 9 was to make the children be impactful in the world," Maiden says. "I know that the most impactful 10 that a child can have is communication."

11 Maiden thought up the idea in 2016, it wasn't until 2021 that her product line was officially launched.

"It took a while because I was 12 ," she admits. "When you create something, you never 13 if people will be receptive (乐于接受的) to it or not…my daughter 14 me to jump and go for it."

She 15 developed four different bears. "Babies are being born every second and communication is the key to everything," adds Maiden.

Overcoming Fear of Failure

Have you ever been so afraid of failing at something that you decided not to try at all? Or has fear of failure meant that, subconsciously, you undermined (削弱) your own efforts to avoid the possibility of a larger failure? It's important to realize that in everything we do, there's always a chance that we'll fail. Facing that chance and embracing it give us a more rewarding life. Here are a few ways to reduce the fear of failing.

Analyze all potential outcomes. Remove that fear by considering all of the potential outcomes of your decision. You can map possible outcomes visually.

Set small goals. Imagining how life will be after you've reached your goal is a great motivator to keep you moving forward. So start by setting a few small goals. Don't focus on the end picture. Just focus on the next step. Taking one small step at a time will help build your confidence, keep you moving towards your final goal.

Learn to think more positively. Every coin has two sides.Learn to change your thoughts and focus more on the bright side of the situation, making you like yourself. Positive thinking is an incredibly powerful way to build self-confidence.

 In some cases, the toughest situation may be genuinely disastrous (灾难性的) and it may be perfectly reasonable to fear failure. In other cases, however, this worst case may actually not be that bad, and recognizing this can help.

A．Look at the worse-case situation.

B．It is up to you to decide which one to look at.

C．Failing at something can help you discover your truest friends.

D．Many of us have probably experienced this at one time or another.

E．If you are afraid of failure, you might be uncomfortable setting goals.

F．These should be goals that are slightly, but not overwhelmingly, challenging.

G．Many people experience fear of failure because they fear the unknown.

The UK government has promised to cut the country's greenhouse gas emissions (排放) by at least 68% by 2030 compared with 1990 levels, marking a significant increase from its current goal.

The new goal comes nine days ahead of the UK hosting a"climate action summit (峰会)"to encourage other countries to declare tougher climate plans, known as Nationally Deter-mined Contributions (NDCs), under the Paris Agreement. Current NDCs will raise temperatures by 3℃. And stronger plans are needed to meet the Paris deal's goal of limiting global warming to

1. 5℃.

"This is the most significant NDCs announcement so far from any major economy," said Richard Black at the Energy and Climate Intelligence Unit, a UK-based think tank, in a statement.

The new goal is exactly in line with what the government's official climate adviser, the Climate Change Committee, called for in a letter published earlier today. The group said 68% would be ""world-leading" compared with existing plans of governments.

The UK had previously promised a 53% cut in emissions as part of a joint (共同的) effort with the rest of the European Union, but the UK is determined to produce a new NDCs. Separately, the UK had also promised a 57% cut by 2032 domestically.

It is clear that far more action will be needed if the UK is to meet the new goal. The government's own analysis last week showed that recent major methods, such as banning newoil-fueled car sales by 2030，had failed to do enough to put the UK on track even for the old goal of 57% by 

2032. The new goal obviously widens that gap further.

Why don't we have eyes in the back of our heads? There are at least two reasons. Eyes are biologically expensive things to make and rear view (后视) eyes don't fit well into the human evolution (进化).

Even animals, such as rabbits, whose main survival advantage is rear vision, have only the side eyes. Rear vision is not so important. There are other species that have evolved this ability by moving the position of their eyes relative to the rest of their head. Many birds have their eyes positioned towards the side of their head, allowing them a very wide angle of vision and, in the case of some birds such as the woodcock, they are positioned so they can actually achieve 360- degree vision. It is also obvious that spiders, which tend to have many eyes, only have them facing forwards.

Humans, and probably some other animals, do have another adapted sense to make it up. Many experiments showed that sounds behind the head were noticed by a listener more than sounds to the front, especially if a listener was in a dark room. So, our ears can make up for the lack of rear-facing vision. You can look at it another way. Rear vision is useful only if the potential threat is visible. During human evolution, that was most often not the case.

Finally, there is often more than one potential "solution" to a given problem. In many species, the answer to maintaining 360 degree awareness of surrounding danger is to rely on many eyes. Social behavior is common in the animal kingdom and one reason for this is that there is safety in numbers. You might be looking the wrong way when a tiger approaches, but if your teammates raise the alarm this is as effective as having eyes in the back of your head.

One day, Amanda was diagnosed (诊断) with cancer of an early stage. During this time, she was admitted to a college. She planned to save money to meet the college expense and then seek medical treatment for the cancer. 

Her father, Clint and her friends didn't want her to put off her treatment due to the expense. They took matters into their own hands and started a GoFundMe campaign. A longtime friend of the family was cofounder of a group named Praynksters, known for random acts of kindness. The friend decided to use their own group to help the family. The group came up with the creative idea to spread the word and invite families, friends, and strangers who wanted to help to take part in a donation activity. The event induced the enormous assistance from the local community.

Clint and Amanda were moved as the crowd passed by and the donations poured in. The event brought the family over $13, 000 in donations to go towards her medical treatments. The generous act of kindness gave the family a comforting, and optimistic feeling during a time when all hope seemed lost. Clint said that Amanda struggled with the idea of asking for help. She felt guilty and undeserving compared to others who are also struggling. She is still humbled by it all. 

After several months of treatment, life for the family has started getting back to their normal routine. Once Amanda got her strength back, she returned to school and completed her bachelor's degree. The family is now inspired to volunteer in their local neighborhood and contribute to crowdfunding (众筹) efforts. They are grateful for the opportunity to give back and help others as many have helped them.

How to plan your routes to avoid busy places

Whether you are a beginner or already a regular runner, these apps will come in handy for planning routes that avoid busy places on your next run

Strava

Just put in whether you're running or cycling, how far you'd like to go and whether you're keen to avoid hills, the app will then suggest a number of routes near you, based on where other runners have been. It is a good way to see running routes you might not have explored.

Komoot

As you plan the route, it'll work out the distance of your run and give you the option to input your running speed, allowing the app to work out how long the route shall take you.

Map my run

Map my run gives runners the option to plan their own route, or the ability to search through popular running routes near you, which is even more helpful for beginners. The app gives you the option of saving your favourite routes and accessing them on the app if you get lost mid-run.

OS Maps

Another hugely popular map-building platform, OS Maps is pretty high tech when it comes to planning a running route. You'll need a subscription to get some of the features, but using the free app you can find local running routes. There are almost two million routes stored in the routes database, and many of them are free.