Many of us remember being in awe(敬畏) when we saw cloned dinosaurs running wild in the film Jurassic Park. And the idea of using technology to revive(恢复) extinct species has long fascinated not only writers and directors, but scientists as well.

    According to The Telegraph, woolly mammoths(长毛猛犸象), which featured in the popular Ice Age animated movie series, “may walk the earth once more” now that scientists have taken another step toward realizing a long-held dream—recreating their DNA.

    Mammoths became extinct around 10,000 years ago. However, since the discovery of near-perfect preserved remains in Arctic permafrost(北极冻土带) in May 2013, a variety of research studies have been carried out since.

    Geneticists from Harvard University analyzed DNA from the remains, looking for genes which separated mammoths from elephants, such as hairiness and ear size. They then used the results to reproduce exact copies of 14 mammoth genes. “It is the first time that mammoth genes have been alive—although so far it has only been done in the lab,” George Church, lead researcher of the project, told the Sunday Times.

    Church then used a new technique which allows scientists to edit DNA carefully, replacing sections of elephant DNA with the mammoth genes. So “we now have functioning elephant cells with mammoth DNA in them,” he said.

    However, Church ruled out the possibility of bringing the mammoths back to life via cloning from frozen remains. He said he “preferred to focus on rebuilding the full mammoth genome(基因组) by analyzing DNA from preserved remains and putting it into the cells of its closest living relative – the Asian elephant,” reported The Telegraph.

    Church argued that the return of the woolly mammoth—or rather, the return of something very similar—could help bring back fragile(脆弱的) ecosystems. However, some scientists believe that bringing back the mammoth would be unethical.

    Professor Alex Greenwood, an expert on ancient DNA, said: “We may face the extinction of African and Asian elephants. Why bring back another elephant from extinction when we cannot even keep the ones that are not extinct around?” he told the Sunday Times. “What is the message? We can be as irresponsible with the environment as we want. Then we'll just clone things back?”

    “Money would be better spent focusing on conserving what we do have than spending it on an animal that has been extinct for thousands of years,” he said.

    Nov. 21 is World Hello Day. It began back in the 1970s as part of an effort to make the world more peaceful. It was created by the United Nations just after the war between Israel and Egypt in 1973. The philosophy (理念) behind it is: Say “Hello” and stop war.

    It sounds like a fine idea, but most of us know that simply saying “Hello” won't bring about world peace. Still, on a smaller range, the simple act of saying hello to someone can make a lot of difference.

    This might not be obvious. After all, it's such a casual thing and requires so little effort. You raise your head to someone as you pass by them in the school corridor (走廊), say “Hello' then it's over.

    Although we might not realize it, a small thing like a greeting can mean a lot to a person. Many people are lonely because they're shy. They find it difficult to communicate with people, even though they want lo. It leads to them feeling cut off.

    On this basis, maybe it's a good idea, not just on Nov. 21, but every day, to remember to say “Hello” to as many people as we can. The stranger who hears your greeting may secretly smile in their heart. You might even make their day.

    Greeting other people is the easiest way to be polite. Politeness is the way we individual humans link up with the rest of the human world outside of our circles of family and friends. Politeness is one of the aspects of culture that make us a society rather than just many individuals living in the same space.

    No one said it better than the French author Joseph Joubert: “Politeness is the flower of humanity''. A “Hello” to a stranger is a small thing, and often neglected (忽视), but through it we can make the world better for another person.

    The possibility of self-driving robot cars has often seemed like a futurist's dream, years away from coming into reality in the real world. Well, the future is apparently now. The California Department of Motor Vehicles began giving permits in April for companies to test truly self-driving cars on public roads. The state also cleared the way for companies to sell or rent out self-driving cars, and for companies to operate driverless taxi services. California, it should be noted, isn't leading the way here. Companies have been testing their cars in cities across the country. It's hard to predict when driverless cars will be everywhere on our roads. But however long it takes, the technology may change our transportation systems and our cities, for better or for worse, depending on how the transformation is managed.

    While much of the debate so far has been focused on the safety of driverless cars, policymakers should be talking more about how self-driving cars can help reduce traffic jams, cut emissions(排放)and offer more convenient and affordable choices to move around. The arrival of driverless cars is a chance to make sure that those cars are environmentally friendly and more shared.

    Do we want to copy or even worsen the traffic of today with driverless cars? Imagine a future where most adults own their self-driving cars. They accept long, slow journeys to and from work on crowded highways because they can work, entertain themselves or sleep on the ride. They take their driverless car to a date and set the empty car to circle the building to avoid paying for parking. Instead of walking a few blocks to pick up a child or the dry cleaning, they send the self-driving minibus. The convenience even leads fewer people to take public transport — an unwelcome side effect researchers have already found in ride-hailing(网约车)services. Policymakers should start thinking now about how to make sure the appearance of driverless cars doesn't worsen the transportation system we have today. The coming technological development presents a chance for cities and states to develop transportation systems designed to move more people, and more affordably. The car of the future is coming. We just have to plan for it.

    Who's in control of your life? Who's pulling your strings? For the majority of us, it's other people-society, colleagues, friends, family or our community. We learned this way of operating when we were very young, of course. We were brainwashed. We discovered that feeling important and feeling accepted was a nice experience and so we learned to do everything we could to make other people like us. As Oscar Wilde puts it," Most people are other people. Their thoughts are someone else's opinions, their lives a mimicry, their passions a quotation."

    So when people tell us how wonderful we are, it makes us feel good. We long for this good feeling like a drug-we are addicted to it and seek it out wherever we can. Therefore, we are so eager for the approval of others that we live unhappy and limited lives, failing to do the things we really want to. Just as drug addicts and alcoholics live worsened lives to keep getting their fix(成瘾物)we worsen our own existence to get our own constant fix of approval.

    But, just as with any drug, there is a price to pay. The price of the approval drug is freedom-the freedom to be ourselves. The truth is that we cannot control what other people think. People have their own agenda, and they come with their own baggage and, in the end, they're more interested in themselves than in you. Furthermore, if we try to live by the opinions of others, we will build our life on sinking sand. Everyone has a different way of thinking, and people change their opinions all the time. The person who tries to please everyone will only end up getting exhausted (tired) and probably pleasing no one in the process.

    So how can we take back control? I think there's only one way-make a conscious decision to stop caring what other people think. We should guide ourselves by means of a set of values- not values imposed from the outside by others, but innate values which come from within. If we are driven by these values and not by the changing opinions and value systems of others, we will live a more authentic, effective, purposeful and happy life.

    Teen Tour Camps at SummerCamps.com

    Rock-N-Water Christian Camps

    Lotus, California, United States      Duration: 4 weeks

    Founded in 1989, Rock-N-Water is a group of highly trained Christians who want to impact young people with the joy of God's Living Word. We focus our program on biblical principles, and we use the help of nature, friendship, and challenge to develop character and have ridiculous amounts of fun.

    Odyssey Expeditions: Caribbean

    Road Town, Tortola        Duration: 3 weeks

    Odyssey Expeditions offers tropical sailing and scuba diving adventures for teenagers, with marine biology, water sports, and scuba certifications at exciting Caribbean locations. Established in 1995, Odyssey is the best opportunity to safely explore the Caribbean aboard a beautiful sailing catamaran. No experience necessary. Reserve your spot before availability. Small groups of 9-12 allow you to have the most fun!

    The G2 Academy Golf Camp

    Bluffton, South Carolina       Duration: variable

    The summer program at G2 is designed specifically for girls empowering them for their future success. Students can join weekly sessions or stay the entire summer! While participating in the G2 Academy Summer Program, students receive G2 Proprietary Training in golf, mental toughness, physical fitness, nutrition, and empowerment.

    Berklee's Aspire: Music Performance Intensive

    Boston, Massachusetts, United States         Duration: 5 weeks

    Berklee's Aspire will give you a taste of Berklee, the preeminent institute of contemporary music and the performing arts. Whether you are in middle school, high school, or beyond, there is a Berklee summer program in music, theater, and/or dance for you. You'll enjoy access to Berklee's state-of-the-art facilities as you learn from faculty who are the very best at what they do, joined by students from all over the world.

    The Hong Kong-Zhuhai-Macau Bridge, the world's longest sea-based project, comprises four parts: a 22.9-kilometer steel bridge, two artificial islands, a submerged sea tunnel extending for 6.7 kilometers, as well as leading bridges that connect the bridge to the cities.

    For a bridge project, designers prefer to build all the structure on the ground, and only choose the tunnel when there is no alternative. However, for the HZMB, the most practical design is to integrate bridge, island and tunnel to form a complete cross-sea channel.

    "The Pearl River Estuary （河口）holds a world-level shipping channel. Smooth traffic should be guaranteed. And the location is near the Hong Kong International Airport. With about 2,000 flights taking off and landing at the airport, the bridge cannot be built too high for safety reasons, said Meng Fanchao, chief designer of the project. ^"But you cannot have a submerged sea tunnel without any support. That forced us to build the artificial islands."

    Chinese engineers declared a trail in installing deep-immersed tunnel tubes. There is no model for us to refer to as all the cases are shallow-buried tubes, said Meng.

    "For lack of experience, the installation of the first tube lasted for 96 hours," said Yin Haiqing, deputy manager of the Project Management Department. "Everyone was exhausted when we made it."

    The 6.7-kilometer tunnel is the world's longest submerged sea tunnel.

    Two artificial islands, covering an area of 200,000 square meters, help create a smooth transition between bridge sections and tunnels. Different from traditional island, the engineers put 120 steel cylinders （圆柱）with a 22-meter diameter （直径）into the seabed, make out the shape of an island, and fill the island with soil. It is an innovative way they adopted to build the artificial island, making it firmer, more efficient and friendly to the marine ecology.

    The HZMB provides a fixed link between the two Chinese economic centres Hong Kong and Macau and the mainland of China at Zhuhai.