You are sitting on the desk. A teacher is writing on the blackboard. Kids are yelling in the playground outside. A book falls off the desk next to you. Suddenly, the teacher hands you a pop quiz.

Don't panic! {#blank#}1{#/blank#} You're in a “virtual（虚拟的）classroom”. Everything you see and hear is coming to you through a computer-operated display that you're wearing on your head like a pair of very big glasses. Wearing this kind of virtual-reality equipment, you can find yourself sitting in a classroom, touring a famous museum, wandering across a strange landscape, flying into space, or playing with a cartoon character. {#blank#}2{#/blank#} Virtual-reality equipment that delivers images and sounds directly to your eyes and ears makes these fake worlds seem lifelike.

Unlike the classroom, the technology is real. It's a type of technology that uses computer programs to imitate real world situation.{#blank#}3{#/blank#} Movie directors and video game producers have been using computers for years to create ever more realistic special effects. Some companies are now building three-dimensional（三维）fantasy worlds in which players, linked by computer networks, appear to meet and go on explorations together.

    {#blank#}4{#/blank#} They see virtual reality technology as a useful tool for learning more about why people act as they do. It could help psychologists deter identify and come up with solutions for behaviors problems, for example.

“We've spent the last 100 years looking for certain laws in how people interact with the real world,” says psychologist Albert. “ {#blank#}5{#/blank#} This is psychologist's dream.”

    How fit are your teeth? Are you lazy about brushing them? Never fear: An inventor is on the case. An electric toothbrush senses how long and how well you brush, and it lets you track your performance on your phone.

    The Kolibree toothbrush was exhibited at the International Consumer Electronics Show in Las Vegas this week. It senses how it is moved and can send the information to an Android phone or iPhone via a Bluetooth wireless connection.

    The toothbrush will be able to teach you to brush right (don't forget the insides of the teeth!) and make sure you're brushing long enough. “It's kind of like having a dentist actually watch your brushing on a day-to-day basis,” says Thomas Serval, the French inventor.

    The toothbrush will also be able to talk to other applications on your phone, so developers could, for instance, create a game controlled by your toothbrush. You could score points for beating monsters among your teeth. “We try to make it smart but also fun,” Several says.

    Serval says he was inspired by his experience as a father. He would come home from work and ask his kids if they had brushed their teeth. They said “yes,” but Serval would find their toothbrush heads dry. He decided he needed a brush that really told him how well his children brushed.

    The company says the Kolibree will go on sale this summer, for $99 to $199, developing on features. The U.S. is the first target market.

    Serval says that one day, it'll be possible to replace the brush on the handle with a brushing unit that also has a camera. The camera can even examine holes in your teeth while you brush.

    With all the traditional media channels, including newspapers, magazines and television shows, shrinking, advertisers are worrying about how they can reach customers. Banners(横幅) ads on our devices are ugly and disturbing. To overcome various digital problems, the ad industry has been serving up a sneaky(不光明正大的) solution: make ads look less like ads and more like the articles, videos and posts around them.

    This trend, called native advertising, has taken over the Internet; even the websites such as NYTimes.com and Wall-Street.com are using it. On Facebook and Twitter, every 10th item or so is an ad; only the small subtitle “Sponsored（赞助）” appearing in light gray type tells you which posts are ads.

    Won't dressing up ads to make them look like reported articles mislead people? Sometimes, yes. An Interactive Advertising Bureau study found that only 41 percent of general news readers could tell such ads apart from real news stories. And it's getting worse. Advertisers worry that the “Sponsored” label discourages readers from clicking, so some websites are making the labels smaller and less noticeable. Sometimes the labels disappear entirely.

    At a recent talk about the difficulty of advertising in the new, small-screen world, I heard an ad manager tell an impressive story. She had gotten a musical performance – paid for by her soft drink client- perfectly inserted（插入）into a TV awards show, without any moment of blackness before or after. “It looked just like part of the real broadcast!” she recounted happily.

    Look, it is great that native advertising works. But if advertisers truly believe in their material, they should have no problem labeling it as advertising.

    For now native ads continue to be a fashion- with no laws governing them and no labeling standard. But that could change; the Federal Trade Commission has begun considering regulation. If the new generation of digital advertisers clean up their act according to the regulation, native ads might become more acceptable.

    The values of artistic works, according to cultural relativism（相对主义）, are simply reflections of local social and economic conditions. Such a view, however, fails to explain the ability of some works of art to excite the human mind across cultures and through centuries.

    History has witnessed the endless productions of Shakespearean plays in every major language of the world. It is never rare to find that Mozart packs Japanese concert halls, as Japanese painter Hiroshige does Paris galleries. Unique works of this kinds are different from today's popular art, even if they began as works of popular art. They have set themselves apart in their timeless appeal and will probably be enjoyed for centuries into the future.

    In a 1757 essay, the philosopher David Hume argued that because “the general principles of taste are uniform（不变的）in human nature,” the value of some works of art might be essentially permanent. He observed that Homer was still admired after two thousand years. Works of this type, he believed, spoke to deep and unvarying features of human nature and could continue to exist over centuries.

    Now researchers are applying scientific methods to the study of the universality of art. For example, evolutionary psychology is being used by literary scholars to explain the long-lasting themes and plot devices in fiction. The structures of musical pieces are now open to experimental analysis as never before. Research findings seem to indicate that the creation by a great artist is as permanent an achievement as the discovery by a great scientist.

    The obsession(痴迷) with perfection among young people has risen by more than 30 percent over the last three decades, a study has found.

    Many of them believe that their environment is extremely demanding and that others judge them strictly, according to analysis of data from more than 40，000 British, Canadian and American university students from 1989 to 2017.

    The research, carried out by the University of Bath and York St John University, found that the degree to which young people attach an unreasonable importance to being perfect, hold unrealistic expectations of themselves and are highly self­critical has increased by 10 percent when compared to previous generations. The authors suggested their findings point to the influence of three decades of neoliberalism(新自由主义) forcing young people to compete against one another.

    Lead author Dr Thomas Curran from the University of Bath's Department for Health said he hoped organisations responsible for safeguarding the welfare of young people, such as schools, universities, and policymakers who shape the environments in which these organisations operate, would “resist the promotion of competitiveness at the expense of young people's psychological health”.

    He said, “Rising rates of perfectionism highlighted in this study is in line with three decades of neoliberalism, which has forced young people to compete against each other within increasingly demanding social and economic aspects.”

    The researches defined perfectionism as a combination of extremely high personal standards and overly strict self­criticism, leading to psychological difficulties.

    Co­author Dr Andrew Hill of York St John University added, “The increase in mental health difficulties among young people makes for a convincing background for our findings. The higher level of perfectionism may be a key contributing aspect to such difficulties. Young people are trying to find ways to deal with increasing demands being placed on them and they are responding by becoming more perfectionistic towards themselves and others.”

You would want to make a good impression when you introduce yourself on the first day in class at your school wouldn't you? In this post, it will cover what to include in your introduction.

The start

You can start with the obvious (明显的) information — your name.{#blank#}1{#/blank#} You can be a bit creative by starting with something different. You can start with an unusual experience or an interesting fact about your city or an unusual hobby.

{#blank#}2{#/blank#}

The city you come from. You may add a sentence or two about the city as well if there is something interesting to talk about.Maybe the city is known for its historic monuments (历史遗迹).{#blank#}3{#/blank#} And if you've lived in different cities, you may briefly (简洁地) mention their names and,as mentioned above, a sentence or two on the most interesting parts of them.

What are your interests and hobbies?

Playing a sport? Traveling? Reading? Kite flying? Or something unusual,such as toy collecting?{#blank#}4{#/blank#} For example if you' ‘re into reading, mention your favorite books, your favorite author, and how reading has influenced you.

Where can you help others?

If you have a strength (长处) others in your class can benefit (受益) from, feel free to share it.For example, if you're good at dancing, you can teach anyone who's interested. If people know your strengths, they'll readily turn to you when they need help.{#blank#}5{#/blank#} And if you think helping others may be a waste of time, you should remember that you too may need help in areas where others are stronger.

A. Where are you from?

B. But that's a common start.

C. Where did you last attend the school?

D. Maybe it's famous for its natural beauty.

E. This is an easy way to make friends in high school.

F. Describe small facts if you've followed the hobby with serious interest.

G. The organizer may ask to include your family and the place you come from in the introduction.