You may have seen a talking parrot on a TV show, in a movie, or even in someone's home. The parrot has learned to copy sounds that people make. Birds are not the only animals that can copy the noises they hear. Dolphins, bats, and some apes also copy sounds. Now we can add elephants to this list of copycats.

    Dr. Joyce Poole is a zoologist. She studies the sounds of elephants. While she was in Kenya, she would hear strange noises made by Mlaika after sunset. Mlaika was a 10-year-old African elephant.

    Mlaika lived near a highway. Dr. Poole says, “I could not tell the difference between Mlaika's call and the distant truck noise.” She and other scientists studied Mlaika's sounds. It turned out that Mlaika was copying the sounds of the trucks driving by. Why would Mlaika copy trucks that she heard going by on the highway? Animals that are able to copy sounds may enjoy practicing new sounds. When they are kept outside of their natural environment, they may copy unusual sounds. That may be why an elephant would copy the sound of a truck.

    “Mlaika was not the only copycat elephant,” Dr. Poole says. Calimero is a 23-year-old male African elephant. He spent 18 years with two female Asian elephants. Asian elephants make chirping sounds (sounds made by birds) to talk with one another. African elephants usually do not make chirping sounds. But Calimero now does. He is copying his Asian elephant friends. Dr. Poole says that elephants need to form bonds with their family and friends. She says, “They make sounds to communicate with each other. When they are separated, they use sounds to keep in contact.”

    Parrots, dolphins, humans, and elephants show that being a copycat is one way that animals and people make new friends and keep old ones.

    After four silent years, British singer Adele Adkins finally introduced herself to the world again with Hello, the opening song from her third album 25, which came out on Nov. 20, 2015.

    Although Adele is a very successful singer now, music wasn't always what she saw herself doing. At age 10, when she saw her grandmother's pain over the death of Adele's grandfather, she pictured herself as a heart surgeon.

     “I wanted to fix people's hearts,” she told the UK music website i-D, remembering the childhood interest she'd had in biology classes until she found out that her real talent was for singing.

    “Adele didn't go to medical school, but many would agree that she still has healing (治愈)powers. Her songs find the kind of memory every listener holds somewhere in their heart. This kind of feeling is what people have always liked in Adele,” said The Telegraph. “She writes a pop diary, sharing the simple secrets of her heart.”

    Most successful pop stars make albums at a fast pace, but not Adele. After her second album 21 won the 2012 Grammy Award for Album of the Year, she made it clear with her label that she would spend “four or five years” making her next album. She told magazine. “I won't come out with new music until it's better than 21.”

    Instead of seeking fame, Adele remained silent and moved to the countryside. In her free time, she loved to watch TV series Teen Mom, American Horror Story, and The Walking Dead.

    Living life as normally as possible is important to the singer's art. “Nobody wants to listen to a record from someone who's not living in the real world,” Adele told i-D.“So I live a low-key life for my fans.”

    Australian scientists are trying to give kangaroo-style stomachs to cattle and sheep in order to cut the greenhouse gases they send out, which is thought to be responsible for global warming.

    Thanks to special bacteria in their stomachs, kangaroo flatulence (肠胃气胀) contains no methane and scientists want to transfer that bacteria to cattle and sheep who produce large quantities of the harmful gas.

    While the usual image of greenhouse gas pollution is a billowing smokestack, pushing out carbon dioxide, farm animals' passing wind contribute a surprisingly high percentage of total emissions in some countries.

    “Fourteen percent of emissions from all sources in Australia are from enteric methane from cattle and sheep,” said Athol Klieve, a senior research scientist with the greensland state government. “And if you look at another country such as New Zealand, which has got a much higher agricultural base, they are actually up around 50 percent,” he said.

    Researchers say the bacteria also make the digestive process much more efficient and could potentially save millions of dollars in feed costs for farmers. But it will take researchers at least three years to isolate the bacteria before they can even start to develop a way of transferring it to cattle and sheep.

    Another group of scientists, meanwhile, have suggested Australians should farm fewer cattle and sheep and just eat more kangaroos. And about 20 percent of health-conscious Australians are believed to eat the national symbol already.

    It's low in fat, it's got high protein levels and it is very clean in the sense that basically it is free-range(放养的) animal,” said Peter Ampt of the University of New South Wales' institute of environmental studies.

    Our cities have never been denser, taller, or busier than they are now, and with that, comes the constant battle for land. But if we look at aerial images of any city center, we can quickly spot plenty of unused space — the rooftops.

    So what can we use this precious resource for? In a growing number of high-density cities, some of it is dedicated to recreation — everything from bars and pools, to soccer pitches and running tracks can now be found atop skyscrapers. But when a rooftop offers access to sunlight, there are two more obvious candidates for its use - agriculture and solar power.

    Green roofs have been growing in popularity for more than a decade, and in some cases, growing in scale too. Green roofs can provide a habitat for birds and insects in an otherwise hostile environment.

    Cities can be several degrees warmer than the surrounding countryside. Green roofs come with the added benefit of mitigating the dreaded urban heat island effect. Trees and green spaces can absorb shortwave radiation, and use it to evaporate water from their leaves — a kind of 'double cooling' effect.

    With food security and urban nutrition ever-higher on the agenda for the United Nations, there's also a worldwide movement of using green roofs for hyper-local food production. In regions with suitable climates, hundreds of different vegetables, fruits, and salad leaves can be grown on rooftops.

    But what about solar power? With so many cities now stopping using fossil fuels, and the costs of solar panels dropping dramatically, PV systems have become the 'go to' option for generating distributed power in built-up areas. And, even with standard commercial panels, the energy gains are dramatic. It is estimated that rooftop PV systems could generate almost 40% of electricity demands nationwide.

    There's no doubt that in both cases, a network of 'productive rooftops' could benefit the local community by supplying a portion of a necessary resource — either food or electricity — while also reducing their environmental burden. But is one better than the other?

    This was the question posed by researchers from MIT and the University of Lisbon in a recent paper in the journal Cities. Focusing on the rooftops of a mixed-use neighborhood in Lisbon, they carried out a Cost-Benefit Analysis. Starting with existing data on everything from installation costs and resources used, to carbon footprint and yield, they modelled the impact that each installation would have on the local community over a period of 50 years.

    And by looking at it that way, they concluded that for Lisbon, the use of rooftops for food production could yield significantly higher local value than solar PV energy generation. Of course, this is very site-specific. There is no one-size-fits-all solution to make cities more sustainable, and anyone who tells you otherwise is massively over-simplifying a complex issue. Now, all I hope is that some of those decision makers start using it.

    When he was a kid, Alex Vardakostas began working in the grill (烧烤店)alongside adult employees. He estimates he has cooked 50,000 burgers (汉堡包).

    Now, Vardakostas co-owns a burger joint called Creator, in San Francisco, California. But he doesn't stand over a grill flipping burgers, and neither do his employees. At Creator, burgers are cooked and assembled entirely by machine. And because it costs less to maintain the machine than to pay a kitchen's worth of employees, burgers cost less.

    Creator is just one example of a growing phenomenon: Automation is taking over more and more jobs. That means work is done by machines or computers instead of people.

    According to a report from McKinsey Global Institute, about 800 million people could be forced out of their jobs by 2030. McKinsey predicts that as technology improves, some tasks will be done more quickly or cheaply by machine, so businesses will install robots or computer Programs to perform them.

    Some jobs are more likely to be automated than others. Machines can do jobs that have three characteristics: They are routine, repetitive, and predictable. Some of these jobs pay low wages and require little education. But others pay well and demand an advanced college degree. Taxi drivers, cashiers, lawyers, and doctors all perform some tasks that can be done by machines.

    So what jobs are safe from automation? Answers include coming up with new ideas or work that involves interacting with other people and building relationships. Jobs in engineering, science, the arts, therapy, and nursing are examples.

    At Creator, Vardakostas hired people to do just that kind of work. Instead of repetitive burger prepping, workers interact with customers and advise them on flavor pairings, like mushroom sauce with pickles and onion jam. "In our world at Creator, all the work is creative and social," Vardakostas says. "And I think that is what we're going to see more of the future."

    Imagine a school where self-awareness is celebrated, students are encouraged to solve maths problems by writing on the walls and applying learned lessons to real life is more important than homework. These are a few of the concepts that makes Space of Mind School unique.

    Located in a home built in 1896 in Florida, US, the program serves students in grades 2 through 12 and will accept kindergarten students next year. It also offers an after-school program for students who attend traditional schools, as well as evening programs for adults and educators and weekend events for families.

    There is a different atmosphere from that of a traditional school building. Tables and brightly colored walls are white boards. In the science room, students are studying climate changes at a weather station, while in the music room, a student is solving an equation (等式) with his academic coach while he connects music theory and maths.

    The daily schedule at the school also stands out. "We don't assign boring or exhausting homework." said Space of Mind founder and CEO Ali Kaufman. "Instead of homework, we ask that they go home and take a video of themselves applying a lesson they learned or cooking a meal for their family that they learned how to make at school."

    For lunch, instead of traditional cafeteria dishes such as pizza, the school offers organic meals made out of products from local gardens and farms. "Our students also run a business at the Delray Beach Green Market on Saturdays so they can understand sustainable living practices and how to run a business," Kafman said.

    " We are also the first school program in Florida to start and end each day with 15 minutes of meditation (冥想)," Kaufman said. "The positive results we have been seeing in the students from meditation are amazing. We are really about infusing social, emotional and creative skills with academic and life skills."