【推荐1】If you want to slow aging, you might want to eat less. This finding is good news—if you were a mouse. The researchers studied mice, not people.

John Price and other researchers studied two groups of mice. One group was able to eat as much as it wanted. The researchers limited what the mice in the other group ate. Their diet had 35 percent fewer calories than the first group of mice.

Price says the mice with the diet restrictions were more energetic and suffered fewer disease. They were not just living longer but seemed to stay younger for a longer period of time.

The researchers found that fewer calories slow down a natural mechanism in cells called ribosomes. Price explains that ribosomes are responsible for making important proteins in the cells. But with fewer calories, they slow down. This gives the cells more time to repair themselves.

The researchers say ribosomes use from 10 to 20 percent of the cell’s energy to make those proteins. Price wrote that because of this, it is impractical to destroy an entire ribosome when it starts to break down. However, repairing individual parts of the ribosome on a regular basis enables ribosomes to continue producing high quality proteins for longer than they would otherwise. This top quality production, in turn, keeps cells and the entire body functioning well.

Price said, “ribosome is a very complex machine, like a car.” “They need maintenance to replace the parts that wear out the fastest. When tires wear out,” he explained,” you don’t throw the whole car away and buy a new one. It costs less to replace the old tires.”

“Food,” he said, “isn’t just material to be burned—it’s a signal that tells our body and cells how to respond.” Price said the findings help to explain how exactly our bodies age. And this may “help us make more educated decisions about what we eat.”

【推荐2】Your Brain Was Made For Walking

If a president, a legendary philosopher, and one of the bestselling authors of all time credited the same secret for their success, would you try to follow it too? What if the secret was something you already knew how to do?     1    .

Get walking! It’s not just some people who made a case for it as a prime creativity booster.     2    A Stanford University study found that participants were 81 percent more creative when walking as opposed to sitting. According to the study, walking outside-versus on a treadmill-produces the most novel and highest quality analogies in participants who walked and then sat down to do creative work.

The movement aspect of walking is obviously key. You’ve probably heard the phrase Exercise your creativity, which refers to the brain as muscle. Our creative mindset is stimulated by physical movement.     3    

But the scenery is almost as important as the sweat. The National Human Activity Pattern Survey reveals that Americans spend 87 percent of their time indoors. Being inside, you’re more likely to stagnation, the antithesis of energy. Without energy, you can’t wonder or create.     4     Just by going outside, you are stepping out of your habitual surroundings and your comfort zone, which is necessary if you want to open your mind to new possibilities.

    5     Engage more closely with your surroundings for the next four weeks. Turn off your phone and give yourself the chance to be present in the world, to hear conversations and natural sounds, to notice the way people move. Walk not just for exercise. Walk for wonder.

【推荐3】Mangroves are trees that typically grow in saltwater along coasts. But some red mangroves end up deep in the rainforests of Mexico’s Yucatan Peninsula. These plants live in freshwater along the San Pedro Martir River. That’s nearly 200 kilometers from the sea. Scientists wanted to know how these mangroves got trapped so far inland. Carlos Burelo was among them. He became curious about these mangroves on a childhood fishing trip there 35 years ago. Burelo saw that the roots of the mangroves grew above ground. This was different from the other trees.

Burelo’s team first investigated where the freshwater mangroves came from. They started by collecting their leaves and then compared their DNA to the leaves from coastal mangroves which were growing along the Gulf of Mexico. The DNA helped identify the origins of the mangroves on the San Pedro Martir River. They had started along the Gulf of Mexico, some 170 kilometers away from the river. The team discovered other evidence that this ecosystem had once been coastal. They discovered 112 other species in this region that are typically found near coasts.

The researchers looked at the soil too. “These sediments (沉积物)near the mangroves revealed exactly what we expected,” says Exequiel Ezcurra, an ecologist at the University of California. In all, the researchers turned up coastal stones, shells of sea snails and clay sediments rich in shell fragments (碎片). These led the researchers to conclude the area used to be part of the ocean long ago.

Computer models of how sea level has changed over time confirmed those findings. The models showed that when sea levels were higher in the past, the ocean merged with the lower basin of the San Pedro Martir River. That would have been around 150,000 to 130,000 years ago. This pushed red mangroves and other species inland.

“This discovery highlights how changes to the past climate have affected the world’s coastlines,” Ezcurra says. “It also offers a chance to better understand how future sea level rise may affect these ecosystems.”

【推荐1】The European Union (EU) is an organization of European countries. The countries are independent and are governed in different ways. In the United Kingdom, for example, the head of state is a king or queen. In France, on the other hand, the head of state is a president. But each of them sends representatives to European Parliament, which has some control over what happens in each of the member countries.

The idea of the EU began in the 1950s. The first members were France, Germany, Belgium, Luxembourg, the Netherlands and Italy. Little by little, the number increased during second half of the twentieth century. By the year 2000, there were 15 member countries. The new count res were Austria, Denmark, Finland, Greece, Ireland, Portugal, Spain, Sweden and the United Kingdom.

In 2004 the EU increased to 25 members. The Czech Republic, Estonia, Hungary, Latvia, Lithuania, Poland, the Slovak Republic and Slovenia, plus the Mediterrranean island s of Cyprus and Malta all be a members.The expanded EU has a population of more than half a bin people twice as big as the population of the US.

【推荐3】Three-dimensional printing, a technology that creates objects layer by layer, has revolutionized (变革) the way we make things. Recently, a group of Chinese scientists took things a step further by using this technology to create realistic replicas (复制品) of human organs.

Previously, it was challenging to create a single material that could print different human organs due to their complexity. The research team from Chinese Academy of Sciences started by using hydrogel (水凝), a soft gel-like material as the main ingredient.

Human organs have various textures (质地), with our brains being the softest. To replicate the hardness of materials like bone, the researchers added metallic elements to the hydrogel and adjusted their ratio (比例) to create the texture of each organ. Besides, to make sure the printing results are correct, the team used light-curing (光固化) technology in the 3D printing process. A special lamp was placed under the printing machine, causing the gel to become solid right after it was printed.

According to the team’s paper published in the journal Advanced Functional Materials, they are able to produce organ models including the brain, lungs, and intestines (肠). These 3D printed organ models are essential for medical researches, such as testing medical equipment and demonstrating surgeries. Compared to live organs and animal models, they are also ethically (伦理上) acceptable since they are printed artificially. They can help researchers develop new treatments more efficiently, due to their lower relative cost, commented the Alliance of Advanced Biomedical Engineering website. However, this method is still developing, and experts are hoping it will be used in the medical field within a decade, according to CNN.

【推荐1】Brian arrived at the San Francisco airport two hours before the flight to Paris. He was wearing three shirts, a jacket, two pairs of socks, a pair of shorts, and two pairs of jeans. He was carrying one small backpack, which was very full, but he didn't have any other luggage(行李). Brian needed to meet a man named Tony before he checked in (办理乘机手续) for his flight. He found Tony near the Air France counter. Tony gave him a round-trip ticket and a small package.

"Give this package to Jean Paul at the airport in Paris. He will have a sign with your name on it. I think you can find him easily," Tony said, "You don't have any luggage, right?"

"Only this backpack," Brian answered. "You said I could bring one carry-on bag."

"That's right. One carry-on bag is fine. Have a good trip."

"Thanks."

Is Brian a criminal (罪犯)? Not at all. He is an air-courier. And he paid only $110 for the round-trip ticket to Paris. Air-couriers get cheap airline tickets because they take important packages and papers to foreign countries. Businesses sometimes need to get packages and papers to people in foreign countries by the next day. Often, the only way they can do this is to use an air-courier company. It is not cheap for a business to send a package with an air-courier, but it is quick.

Every year about 80,000 people worldwide travel as air-couriers. The number of tickets for the air-courier travel is growing by about 10 percent a year. However, air-courier travel isn't for everyone. But if you have very little money, you can be flexible (灵活的) about your travel plans, and don't mind wearing the same clothes for a week, it can be a great way to take a vacation!

【推荐2】I've loved my mother's desk since I was just tall enough to see above the top of it as mother sat doing letters. Seeing what Mother was doing, I thought that the act of writing must be the most wonderful thing in the world.

My mother was a kind person, who always showed her love on me in action. However, as a little girl, I only wanted heart-to-heart talks between mother and daughter. But such talks never happened. I was sad about it and often rude to her, eager to start a new life somewhere else.

When I had my own family, I came to understand mother's love. So I wrote to mother and asked if she'd forgiven my rudeness. Then, I posted the letter and waited for her answer, but it never came. I felt disappointed and slowly didn't care too much about it.

Years later, during mother's final illness, she left some things for my sister and brother. "But the desk," she said in a weak voice, "is specially for Elizabeth." When I cleaned the desk---her present for me, I found a one — page letter inside, folded many times. It was the letter that I wrote years ago.

Then, tears came down, “Oh, dear mom, you've chosen the silent act to show you did forgive me and always be proud of my writing. Thank you for your silent love. I love you forever!"

【推荐3】Inside a brightly-lit classroom, around 20 schoolchildren are singing the Chinese national anthem. That song is followed by another tune in Chinese—one typically sung during the Lunar New Year. But this scene is not taking place in a Chinese school but at Lakewood Premier school, thousands of kilometers away in Nairobi(内罗比). Here, schoolchildren are learning Mandarin, a language spoken by nearly 1 billion people almost 8,000 kilometers away from their home. More will join their ranks in 2020 when Mandarin will be officially taught in all Kenyan schools alongside French, Arabic and German, which are already on the curriculum.

Sandra Wanjiru, 13, is one of hundreds of African schoolchildren who are increasingly skilled in the Chinese language. Lakewood Premier School, where Wanjiru studies, has begun the program a year early to give its pupils a head start. "I chose to learn Chinese first not only because it's interesting to learn a foreign language but also because I would want to travel and do business in China," said Wanjiru.

Julius Jwan, CEO of the Kenya Institute of Curriculum Development (KICD) told Chinese state-owned Chinese news agency Xinhua： "The place of China in the world economy has also grown to be so strong that Kenya stands to benefit if its citizens can understand Mandarin. " China has become increasingly powerful across Africa over the past two decades. Through President Xi Jinping's flagship Belt and Road Initiative, China has loaned money to African countries to build highways, dams, stadiums and airports.

Henry Adramunguni, a specialist at Uganda's National Curriculum(课程)Development Centre, said Mandarin was included in the curriculum because it is one of the United Nations' languages of work. "We want to give the opportunity for our young Ugandans to have access to jobs, education and business beyond our borders. That's why we've given them this opportunity to learn Chinese," he said,