See a cellphone cover that you like on Taobao? Forget about placing an order, paying the bill online and waiting for days for it to be delivered to you. In the near future, you'll be able to get it in minutes just by hitting “print” on your computer.

    You might find it hard to believe that you could actually “print” an object like you would a picture. But it is not that hard to understand how it would work. Just as a traditional printer sprays ink onto paper line by line, modern 3D printers spread material onto a surface layer by layer, from the bottom to the top, gradually building up a shape.

    Instead of ink, the materials the 3D printer uses are mainly plastic, resin(树脂) and certain metals. The thinner each layer is—from a millimetre to less than the width of a hair—the smoother and finer the object will be.

    This may sound like a completely new technology, but the truth is that 3D printing has been around since the late 1980s. Back then, it was barely affordable for most people, so few knew about it.

    Last year, though, saw a big change in the 3D printing industry—printers became much cheaper. For example, 10 years ago a desktop 3D printer might have cost ￡20，000, while now they cost only about ￡1，000, according to the BBC.

    Taken out of the factory and introduced to more diverse and common uses, 3D printing can create just about anything you can think of—flutes , bikinis, jewelry, aircraft parts and even human organs. In fact, scientists from Cornell University in New York have just made an artificial ear using a 3D printer, according to Science Daily. The fake ear looks and acts exactly like a natural one.

    However, as 3D printing becomes more common, it may bring about certain problems—such as piracy. “Once you can download a coffee maker, or print out a new set of kitchen utensils (餐具) on your personal 3D printer, who will visit a retail  store again？” an expert in 3D printing told Forbes News. Even more frightening, what if anyone in the world could use a 3D printer to print out a fully functioning gun?

    Something about the four World Famous Statues

    The Little Mermaid

    The statue The Little Mermaid sits on a rock in the Copenhagen harbor at Langelinie in Denmark. Tourists visiting for the first time are often surprised by the relatively small size of the statue. The Little Mermaid is only 1.25 meters high and weighs around 175kg. designed by Edvard Eriksen, the statue was erected in 1913 to commemorate（纪念）the fairy tale The Little Mermaid. The poor lady has lost her head several times but each time it has been restored. Copenhagen officials announced that the statue may be moved further out in the harbor, as to avoid further vandalism(故意破坏)and to prevent tourists from climbing onto it.

    David Statue

    David is a masterpiece of Renaissance sculpture sculpted by Michelangelo from 1501 to 1504. The 5.17 meter marble statue portray the hero after his victory over Goliath, Michelangelo chose to represent David before the fight contemplating(沉思)the battle yet to come. To protect it from damage, the famous statue was moved in 1873 to the Accademia Gallery in Florence in Italy, where it attracts many visitors. A replica was placed in the Piazza della Signoria, at the original location.

    Great Sphinx

    Located at the Giza Plateau near Cairo in Egypt, the Great Sphinx is one of the largest and oldest statues in the world, but basic facts as who was the model for the face, when it was built, and by whom, are still debated. It is the largest monolithic(独块巨石的)statue in the world although it is considerably smaller than the pyramids around it. Despite conflicting evidence and viewpoints over by the years, the traditional view held by modern Egyptologists at large remains that the Great Sphinx was built in approximately 2500 BC by the Pharaoh Khafre, the supposed builder of the second pyramid at Giza.

    Statue of Liberty

    The Statue of Liberty, a gift from the people France to celebrate the centennial of the signing of the United States Declaration of Independence, stands upon Liberty Island and is one of the most famous symbols in the world. It represents a woman wearing a stole, a radiant crown and sandals, trampling a broken chain, carrying a torch her raised right hand and a tabula ansata tablet in her left hand. The construction of the statue was completed in France 1886 until the jet age, it was often one of the first glimpses of the United States for millions of immigrants.

Senses That Work Together

    When we think about how our senses work, we usually imagine them operating separately: you sniff a flower, and the smell is delivered uninterrupted from nose to brain. However, it's more complex than that. Most evidence for cross-modal perception (知觉) comes from studies into sound and vision (视觉). But research that shows other senses crossing over is coming out all the time, and it seems that even sound and smell sometimes form an unlikely pairing.

    When New York researchers, Daniel Wesson and Donald Wilson, tried to find out the truth about a “mysterious” area of the brain called the olfactory tubercle (嗅结节)，they had to deal with this fact. Originally, they only intended to measure how olfactory tubercle cells in mice responded to smell. But during testing, Wesson noticed that every time he put his coffee cup down with a clunk (哐啷声)，the mouse cells jumped in activity. In fact, the olfactory tubercle is well-placed to receive both smell and sound information from the outside world. Later they found that among separate cells, most responded to a smell but a significant number were also active when a sound was made. Some cells even behaved differently when smell and sound were presented together, by increasing or decreasing their activity.

    Of course, mice aren't people, so research team has been carrying out further experiments. They pulled together a group of people and gave them various drinks to smell. Participants were asked to sniff the drinks, and then match them to appropriate musical instruments and produce the notes at different levels. The results were interesting: piano was regularly paired with fruity fragrances; strong smells sounded like the instruments that are made of metal.

    Further research found that listening to different sounds can change your perceptions. Studying taste this time, the team ordered some special toffee (太妃糖)and put together “soundscapes” corresponding to bitterness and sweetness. Participants tasted similar pieces of toffee while listening to each soundscape, and found the toffee more bitter or sweeter, depending on which soundtrack they were listening to.

    Studies like this are helping scientists correctly describe our understanding of the senses, and how the brain combines them with its advantage. The consequences are worth considering. Could we see musicians work together with chefs to produce sound-improved food and drink? Will you be ordering a coffee with a soundtrack to bring out your favorite smell? Come to think of it, that could be one thing you hope coffee shop chains don't get round to.

    Your weight has been important since the moment you were born. Maybe you even know what your birth weight was. Most newborns weigh between 6 and 9 pounds, but some may weigh more and some less. But very quickly, a baby gains weight and everyone is glad about that because it means the child is growing bigger and stronger.

    As you get older, your weight is still important. It's something your parents and doctor will probably keep an eye on. When you go for a checkup, the doctor often will record your height and weight and compare it with what it was the last time you came in. The doctor wants to check whether you have a healthy weight because weighing too much or too little can be a problem.

    But these days, being overweight is more common than being underweight. In the last 30 years, a growing number of kids and teenagers have developed weight problems. Today, 1 out of 3 kids and teens between the ages of 2 and 19 are overweight. Many grown-ups understand what it's like to have weight problems, since 2 out of every 3 adults(成年人) are overweight.

    For kids and adults, weighing too much can lead to illnesses and health problems. And a kid who is overweight might be made jokes on or find it hard to keep up with friends on the playground. When people talk about being overweight, they mean that someone has more body fat than is healthy. Everyone has some body fat, but extra (多余的) fat can influence someone's health and ability to walk, run, and get around, as well as how the person looks and his or her self-respect.

    Teenagers in America know that they'll possibly need technical skills to find good jobs, but a new survey reveals that interest in technology-related careers may be decreasing.

The percentage of boys aged 13 to 17 who are interested in science, technology, engineering and math —or STEM —careers dropped from 36 percent in 2017 to 24 percent this year, according to a survey by Junior Achievement USA. The amount of girls interested in STEM careers stayed unchanged at II percent.

    But the 1, 000 survey participants still named technology as one of two key skills that will be necessary to prepare them for their future careers.

    "Kids don' t understand how technology can be applied to careers in addition to computers, and maybe robotics, "said Tammera L. Holmes, president of aviation consulting firm AeroStar Consulting （航空资询公司）.“That's all they know, so they can't really translate that interest to career pathways."

    When Holmes was in high school, her mom sent her to an event that featured (以......为专题)the pilots from World War II. One of the pilots took her for a ride and let her take the wheel immediately that was the career for me." she said.

    Women remain outnumbered(超过) by men in fields like technology. For people working to increase the number of women in these areas, the lack of growth in girls interest in STEM careers is concerning.

    Teenage girls are more interested than their male classmates in running after careers in which they can help others, said Ed Grocholski from Junior Achievement. Even with all the programs aimed at increasing girls' interest in STEM, "I don't think we really talk that much about how we improve people's lives through STEM," Grocholski said.

    Society needs to do better at making those connections for kids, said Katherine Latham, founder of an engineering firm. She used civil engineering as an example of a career that will continue to be important.

    However, the fact that students know they will need tech skills in their future careers is encouraging.

    The second skill they said they need is relationship-building.

    "That's going to be the new type of engineers," Latham said.

Coco Gauff used to visit the Grand Slam tournament (大满贯锦标赛) as a kid to see her idols Serena and Venus Williams. Now she is a champion there herself. On Sept 9, the 19-year-old from the US won her first major women's singles title at the 2023 US Open (美国网球公开赛).

After an average start, Gauff surged to a 2-6, 6-3, 6-2 victory over her bigger, stronger opponent, Aryna Sabalenka, from Belarus, who became the new world No.1 the day after the tournament ended.

Unlike the Williams sisters, who have obvious force and power, Gauff is small and slim. But she moves fast on the tennis court. Forbes magazine said, "She is the quickest and perhaps already the best returner of impossible shots in tennis history."

Even though Sabalenka is a very powerful hitter, it felt like she had to finish each point four or five times, as Gauff's defense was so perfect, noted The Telegraph. This ended up frustrating Sabalenka and caused her to make 46 unforced errors.

Gauff thus became the first American teenager to win the US Open since Serena Williams, then 17, in 

1999. When asked about "taking the torch" from the 23-time Grand Slam winner and the similarity between their tennis careers, Gauff told ESPN, "Serena is Serena. She's the greatest of all time... I'd hope to do half of what she did. But I'm not going to compare myself to her. She's some one that I look up to."

Now, Gauff's big win has left tennis fans wondering: When's her next Grand Slam? That's no easy task. Two of the past four US Open women's champions were teenagers at the time, Canada's Bianca Andreescu in 2019 and the UK's Emma Raducanu in 2021, and neither has come close to repeating their success yet. But one thing about Gauff is certain — that at just 19 years old, the sky's the limit.