Using technology, of course. While special services via webcam(摄像头) and cheating detecting software have been developed now, Mettl, an online company, has developed advanced techniques for netting cheaters, which the company claims are even more reliable and easier to use. Whatever small attempt to cheat, he or she will be found out.

    Mettl has adopted a handful of technologies on its test—taking platform, creating a mini monitoring state in an exam. Here's how it works: A test-takersigns on to Mettl and selects hisher exam from the site's library of pre—loaded tests. Facial and keystroke recognition technology confirm the person that has signed in is the very person, and the system records both the test—taker(through the webcam)and the test—taker's screen throughout the test.

    Mettl's technology uses the test—taker's webcam to detect how many people are using the computer. Soon, it will track eye movement well enough to sense whether the test-taker is looking away from the screen, perhaps to Consult a smart phone or a friend in secret. Mettl also monitors the test-taker's screen and can detect when the test-taker has changed a computer or moved from the test. The system will soon be able to record sound, thus detecting whether the test-taker is talking or being talked to.

    If any irregularities are detected, the system flags the incident and reports it back to the test's administrator. This can bring any number of things, depending on the test-giver's wishes: a completeshutdown of the exam, a warning message that appears on the test-taker's screen, even human instructions from the control center.

    Mettl is hoping its technology will help it break into the country's big MOOC markets.

    Kung fu is one of the most popular topics of discussion among foreigners talking about China. As a discipline of kung fu with the largest number of practitioners in China, Tai Chi is gaining popularity worldwide. Tai Chi is sweeping the world thanks to its deep cultural roots and the health benefits coming from practicing it.

    The philosophy of Tai Chi features the concept of yin and yang, which is typical of Confucianism and Taoism. Tai Chi also takes in ideas from traditional Chinese medicine, including anatomy (解剖学) and physiology (生理学). It is a practice that couples hardness with softness, and it is a perfect example of traditional Chinese culture.

    Through lasting practice, learners begin to feel the positive impact (影响) of Tai Chi on their health. Unlike kung fu practices that focus on attacking and defending against enemies, Tai Chi focuses more on shaping good characters and keeping fit. By practicing Tai Chi, people will feel an improvement in their physical and psychological health by promoting a balance between yin and yang within their bodies. This is similar to Western medicine's improving people's self-healing ability and immune system.

    Tai Chi is playing an important role in presenting Chinese culture to the rest of the world, acting like a bridge between China and other countries. Recent years have seen a lot of international communication on Tai Chi. In provinces like Hebei, Henan, Shanxi and Shaanxi, where Tai Chi teaching and learning are particularly active, local governments and non-governmental institutions often organize activities and competitions for learners and fans to attend and participate in. Large sporting events hosted by China such as the Asian Games and Olympics have featured Tai Chi performances or contests. These activities have opened a window for the outside world to know more about Tai Chi, paving the way for its overseas wide spread.

    Today, Tai Chi not only belongs to China, but also to the whole world and to everyone who loves it.

    Robots make me nervous—especially the ones which seem to think for themselves. I was embarrassed to admit this till I heard that Bill Gates, the founder of Microsoft, felt the same way.

    Gates said in an interview with the social networking and news website Reddit: "I am in the camp that is concerned about super intelligence. First the machines will do a lot of jobs for us and not be super intelligent．That should be positive if we manage well. A few decades after that, though, the intelligence is strong enough to be a concern."

    Well, maybe I don't have to worry about my computer and kitchen equipment yet. After I use them I can always pull the plug. But in the future, machines might find a way to prevent us from switching them off. There's a terrible thought!

    Maybe the problem with computers too clever for us is not that they are evil like some we've seen in sci-fi movies. What could put us in danger is that they might be too efficient. That's what philosopher Nick Bostrom from Oxford University believes. He says that machines are indifferent to humans and in pursuit of their own goals，the destruction of people might be just additional damage. Bostrom gives us an example: A machine which might have its only goal to produce as many paperclips as possible might look at human bodies as extra material for paperclips and go after you. Because it is, well, a machine, it would not take pity on you.

    It's a good thing that American writer Isaac Asimov thought about how far robots can go and left us his three rules of robotics. They state that a robot may not hurt a human being or allow the human being to come to harm.

    I'm glad my machines at home are "dumb". All my cleaner wants to take over is the carpet in my living room. Let's hope they don't create an appliance which wants to take over the world!

    How does a sunset work? We love to look at one, but Jolanda Blackwell wanted her eighth-graders to really think about it and question.

    So Blackwell had her students watch a video of a sunset as part of a physics lesson on motion. "I asked them: ' So what's moving And why' " Blackwell says. Some thought the sun was moving; others knew that a sunset is the result of the Earth spinning around on its axis. "Usually, my biggest challenge is trying to keep them patient," she says. "They just have so many burning questions."

    "Every day, we meet new information," says Charan Ranganath, a psychologist. Ranganath was curious to know why we keep some information and forget other things. So he got 19 volunteers and asked them to review more than 100 questions. When the participants' curiosity was aroused, the parts of' their brains that regulate pleasure and reward lit up. Curious minds also showed increased activity in the brain, which is involved in greater memories.

    "Curious brains are better at learning not only about the subject at hand but also dull information. This is a phenomenon teachers can use in the classroom," says Evie Malaia, a professor. "Say a kid wants to be an astronaut," she says. NL Well, how do you link that goal with learning multiplication tables(乘法表)" "A teacher may choose to ask her class an interesting word problem that involves space exploration," Malaia says. Students may remember the answer to the word problem, but they'll also remember how they found the answer through multiplication.

    What Ranganath wants to know most is why some people seem naturally more curious than others. Lots of factors, including stress, aging and certain drugs  affect dopamine(多巴胺) processing in the brain. "If we could figure these things out, we could help those who may just seem bored," Ranganath says.

    Blackwell says she doesn't have to deal with that problem too often. She says her students love exploring the mysterious unknowns in science: What happens when a car crashes. How do rainbows work "I tell my kids there's no dumb questions," Blackwell says. "That's science: asking questions and seeking answers."

I traveled to Hawaii several months ago, in part to cover a story on invasive plants and animals and their impact on the state. As I worked on this story, I kept thinking about the fact that some plants and animals become uncontrollably invasive when they're brought into a new ecosystem, while others don't. For example, over the past two hundred years or so, there have been approximately 20, 000 non-native plant species either intentionally or accidentally brought into Hawaii alone. But only a small part of those plants — 200 species or so — have become invasive, threatening the environment, the economy, or human health. 

An example from Hawaii's forests: the invasive plant strawberry guava thrives as it gives off a chemical that prevents all other plants from growing nearby, and it also absorbs more water than native species. What makes these particular species so successful? Most of the reasons involve how a particular species interacts with its new environment. First, invasive species may be highly adaptable to a variety of climates. Second, they are usually quite fecund (多产的), which ensures that they can multiply rapidly. Third, they are usually threatening when it comes to resources like nutrients and space, easily crowding out their native counterparts (对应的物种). And finally, invasive species thrive when there are no natural enemies or pests in their new space.

How can we eradicate invasive species once they're in place? Unfortunately, it's nearly impossible to do that — conservationists would have to notice that the species is a problem before its population has established and grown to an uncontrollable size. Instead, most conservationists battling invasive species aim for control in key ecological pockets.

It is a constant battle, though, and humans are always playing catch-up. If you're thinking of planting unusual plants in your garden or keeping a foreign pet, perhaps reconsider and go for a native one. You never know when they might escape and tip over an ecosystem.

Going to concerts and live performances is a lot of fun. As a teen, you'll want to prepare for the event far in advance in order to ensure that your concert experience is enjoyable.

Check to make sure that the concert venue(场所) is for all ages.

Some venues, particularly those that serve alcohol, will only allow entry for guests who are over 21 years old. {#blank#}1{#/blank#} If you buy a ticket and get turned away at the door, you likely will not get your money back.

Ask your parents for permission.

{#blank#}2{#/blank#} Have a conversation with your parents to figure out how you will travel to and from the concert, and talk about ground rules for staying safe at the event.

Find a friend to go with.

For your safety, it's best not to attend concerts alone. {#blank#}3{#/blank#} If you're having trouble finding company, consider posting on Facebook, Twitter, or Instagram to see if other people in your social network are interested.

Buy tickets.

If the concert is for a popular band, figure out exactly when the tickets go on sale. {#blank#}4{#/blank#}Ticketmaster. com sells tickets for bigger shows, but if you're going to a smaller show, look online at the venue's website for information on how to buy tickets.

Research venue policies and regulations.

Find the venue's web page to get a sense of what to expect, and to avoid any problem on the day of the concert. You should know how early the doors will open. {#blank#}5{#/blank#}