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.

    If you want to become a fluent English speaker you should take some advice: There are four skills in learning English. They are reading, listening, speaking, and writing. The most important thing you must remember is that if you want to improve your speaking and writing skills you should first master the skills of reading and listening.

    Read as much as you can. But your reading must be active. It means that you must think about the meaning of the sentence, the meaning of the unfamiliar words, etc. There is no need for you to pay much attention to grammars or try to understand all the unfamiliar words you come across ， but the fact that you see them for the first time and recognize them whenever you see them, for example, in other passages or books, is enough. It would be better to prepare yourself a notebook so you can write down the important words or sentences in it.

    As for listening, there are two choices: besides reading, you can listen every day for about 30 minutes. You can only pay attention to your reading and become skillful at your reading, then you can catch up on your listening. Since you have lots of inputs in your mind, you can easily guess what the speaker is going to say. This never means that you should not practice listening.

    For listening you can listen to cartoons or some movies that are specially made for children. Their languages are easy. Or if you are good at listening you can listen to VOA or BBC programs every day. Again the thing to remember is being active in listening and preferably taking some notes.

    If you follow these pieces of advice, your speaking and writing will improve automatically, and you can be sure that with a little effort they will become perfect.

    In 1941, science fiction writer Isaac Asimov stated the Three Laws of Robotics. These laws come from the world of science fiction, but the real world is catching up. A law firm gave Pittsburgh's Carnegie Mellon University $10 million to explore artificial intelligence. Peter Kalis, chairman of the law firm, K&L Gates, said the development of technology had led to questions that were never taken seriously before. What will happen when you make robots that are smart, independent thinkers and then try to limit their freedom?

    Researcher Kalis said, “One expert said we'll be at a point when we give an instruction to our robot to go to work in the morning and it turns around and says, 'I'd rather go to the beach.'” He said that one day we would want laws to keep our free-thinking robots from running wild.

    With the law firm's gift, the university will be able to explore problems now appearing within automated industries. “Take driverless cars for example,” Kalis said. “If there's an accident concerned with a driverless car, what policies do we have in place? What kind of insurance policies do they have?” In fact, people can take a ride in a driverless car in Pittsburgh where an American online transportation network company uses the city as a testing ground for the company's driverless cars.

    The problems go beyond self-driving cars and robots. Think about the next generation of smartphones, those chips fixed in televisions, computers, fridges, etc., and the ever-expanding collection of personal data being stored in the “cloud”. So can Asimov's Three Laws of Robotics be used in reality? Is it necessary to have a moral guideline that everyone can understand? Whatever it is, doing no harm should be the very first one.

    One day, Mr. Arnold was teaching a lesson, and things were going as normally as ever. He was explaining the story of human being to his pupils. He told them that, in the beginning, men were nomads (游牧); they never stayed in the same place for very long. Instead, they would travel about, here and there, in search of food, wherever it was to be found. And when the food ran out, they would move off somewhere else.

    He taught them about the invention of farming and keeping animals. This was an important discovery, because by learning to cultivate (耕作) the land, and care for animals, mankind would always have food steadily. It also meant that people could remain living in one place, and this made it easier to set about tasks that would take a long while to finish, like building towns, cities, and all that were in them. All the children were listening attracted by this story, until Lucy jumped up:

    “And if that was so important and improved everything so much, why are we nomads all over again, Mr. Arnold?”

    Mr. Arnold didn't know what to say. Lucy was a very clever girl. He knew that she lived with her parents in a house, so she must know that her family were not nomads; so what did she mean?

    “We have all become nomads again,” continued Lucy, “The other day, outside the city, they were cutting the forest down. A while ago a fisherman told me how they fish. It's the same with everyone: when there's no more forest left the foresters go elsewhere, and when the fish run out the fishermen move on. That's what the nomads did, isn't it?

    The teacher nodded, thoughtfully. Really, Lucy was right. Mankind had turned into nomads. Instead of looking after the land in a way that we could be sure it would keep supplying our needs, we kept developing it until the land was bare. And then off we would go to the next place! The class spent the rest of the afternoon talking about what they could do to show how to be more civilized (文明的).

    The next day everyone attended class wearing a green T-shirt, with a message that said “I am not a nomad!”

    And, from then on, they set about showing that indeed they were not. Every time they knew they needed something, they made sure that they would get it using care and control. If they needed wood or paper, they would make sure that they got the recycled kind. They ordered their fish from fish farms, making sure that the fish they received were not too young and too small. They only used animals that were well cared for, and brought up on farms.

    And so, from their little town, those children managed to give up being nomads again, just as prehistoric men had done, so many thousands of years ago.

The situation is that familiar — deadlines are approaching, time runs out, disorder and confusion fills the day. The feeling is just as familiar — a slightly faster heart rate, and shortness of breath. Yes, it is panic time.

    It's too late to kick yourself with "I should have started on this sooner." or "It was a mistake to accept this tight deadline." The only thing left to deal with the situation is to panic more efficiently.

    ① Focus.

Panic happens when you are on an overload — too many things to do, too much pressure, too little time. But if you focus on the tasks that you need to take care of, and line them up in a logical list, you can have better control of a highly stressful and wild situation.

    ② Get rid of distractions.

    Time wasters and unnecessary activities are the last things you need during this time. Let everyone know you are on panic mode and should not be disturbed unless it is an emergency.

    ③ Watch your time.

    Don't be too engaged in one detail so that you reduce your timing for the other important details. Mind the time and deal with each task so that you can finish all of the required activities sufficiently.

    Try to solve a panic situation as quickly as you can so that you can rest and get back your energy and strength for the next one.

    Plastic waste has polluted the Arctic. Two new studies have spied bags, fishing rope and tinier bits of rubbish in the Barents Sea. This sea sits north of Norway, Sweden, Finland and Russia. It mixes with the Arctic Ocean, which is even farther north.

    Plastic waste in the Arctic could harm wildlife and may hint that large volumes of human rubbish are collecting there, says Melanie Bergmann. She is one of the scientists who spotted the waste. She studies Earth's oceans at the Alfred Wegener Institute in Bremerhaven, Germany. She first started counting bits of plastics in the Barents Sea because she kept spotting signs of the stuff there in images taken with deep-sea cameras.

    Bergmann and her colleagues counted pieces of plastic from an icebreaker, a boat designed to break through large blocks of ice in very cold waters. They also tracked plastic pieces they saw during helicopter rides over Arctic waters. The team found 31 pieces of plastic. “That doesn't seem like much, but it shows us that we've really got a problem, one that extends even to this remote area, far from civilization,” Bergmann says. She and her colleagues described their findings October 21 in Polar Biology.

    Another team has also been counting plastics in the area. Those scientists took water from the Barents Sea and counted the number of smaller bits of plastics, called microplastics.

    Plastic in the ocean is dangerous to animals. Some may get caught in rope or bags. And wildlife may swallow bags and other plastic bits. That makes them feel full. But some may eventually starve because they are not getting the nutrients they need to live. Sometimes plastics also may break down in an animal's body and release poisonous chemicals. If another animal later eats the one that swallowed plastic, it too can end up with poisonous chemicals in its body. This, in turn, can travel up the food web, endangering predators (肉食动物) — even people.