Since Edmund Hillary and Tenzing Norgay climbed Mount Everest, Mount Qomolangma's peak is no longer a lonely place and is turning into a trash heap.

    So far, more than 350 climbers have successfully reached the peak. And they have complained about waiting for hours in the bottlenecks (狭窄路段) on the way to the peak, a situation that isn't just uncomfortable — it's cold and windy up there — but downright dangerous. If bad weather strikes, climbers can and do die.

    As a matter of fact, the dangerous crowds aren't the only problem on Qomolangma. All those climbers need to bring a lot of gear—and much of them ends up being left on the mountain, sometimes even the peak itself. Mount Qomolangma is becoming the world's largest dump. Here's mountaineer Mark Jenkins writing in National Geographic about the state of Qomolangma: “The two standard routes, the Northeast Ridge and the Southeast Ridge, are disgustingly polluted with oxygen cans and torn tents everywhere.”

    But the good news is that some mountaineers are taking it upon themselves to clean up Qomolangma. Mountianeer Paul Thelen and his friend Eberhard Schaaf are part of the annual Eco Everest Expedition, which has been cleaning up rubbish from base camps to the peak since 2008. So far they've collected over 13 tons of garbage.

    Some of that rubbish is even being used for a higher purpose. As part of the Mount Everest 8844 Art Project, a group of 15 artists from Nepal collected 1.5 tons of garbage brought down the mountain by climbers. They've transformed the cans and oxygen tanks—and in one case, part of the remains of a helicopter—into 74 pieces of art that have already gone on exhibition in Nepal's capital. Part of the profit from sales will go to the Everest Peakers Association, which has helped collect tons of rubbish on the slopes of the mountain.

    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.

    A city child's summer is spent in the street in front of his home, and all through the long summer vacations I sat on the edge of the street and watched enviously（嫉妒地） the other boys on the block play baseball. I was never asked to take part even when one team had a member missing—not out of special cruelty, but because they took it for granted I would be no good at it. They were right, of course.

    I would never forget the wonderful evening when something changed. The baseball ended about eight or eight thirty when it grew dark. Then it was the custom of the boys to retire（撤退） to a little stoop(门廊) that stuck out from the candy store on the corner and that somehow had become theirs. No grownup ever sat there or attempted to. There the boys would sit, mostly talking about the games played during the day and of the game to be played tomorrow. Then long silences would fall and the boys would wander off one by one. It was just after one of those long silences that my life as an outsider changed. I can no longer remember which boy it was that summer evening who broke the silence with a question: but whoever he was, I nod to him gratefully now. "What's in those books you're always reading?" he asked casually. "Stories," I answered. "What kind?" asked somebody else without much interest.

    Nor do I know what drove me to behave as I did, for usually I just sat there in silence, glad enough to be allowed to remain among them; but instead of answering his question, I told them for two hours the story I was reading at the moment. The book was Sister Carrie. They listened bug-eyed（瞪大眼睛的） and breathless. I must have told it well, but I think there was another and deeper reason that made them to keep an audience. Listening to a tale being told in the dark is one of the most ancient of man's entertainments, but I was offering them as well, without being aware of doing it, a new and exciting experience.

    The books they themselves read were the Rover Boys or Tom Swift or G.A.Henty. I had read them too, but at thirteen I had long since left them behind. Since I was much alone I had become an enthusiastic （狂热的）reader and I had gone through the books-for-boys series. In those days there was no reading material between children's and grownups 'books or I could find none. I had gone right from Tom Swift and His Flying Machine to Theodore Dreiser and Sister Carrie. Dreiser had hit my young mind, and they listened to me tell the story with some of the wonder that I had had in reading it.

    The next night and many nights thereafter, a kind of unspoken ritual (仪式) took place. As it grew dark, I would take my place in the center of the stoop and begin the evening's tale. Some nights, in order to taste my victory more completely, I cheated. I would stop at the most exciting part of a story by Jack London or Bret Harte, and without warning tell them that that was as far as I had gone in the book and it would have to be continued the following evening. It was not true, of course; but I had to make certain of my new-found power and position. I enjoyed the long summer evenings until school began in the fall. Other words of mine have been listened to by larger and more fashionable audiences, but for that tough and athletic one that sat close on the stoop outside the candy store, I have an unreasoning love that will last forever.

    When returning to south-western Germany, where my parents live, it is compulsory for me to go on a hike to connect with nature and reconnect with myself. So, that is exactly what I did the first sunny Sunday back in the beautiful Black Forest. The Huzenbacher See is a tarn in the middle of the northern Black Forest with abundant nature surrounding it. Approaching it after a good hour walk, I saw fascinating blue dragonflies in quantity that attracted us by the way they flew around. They didn't stand still for a photo, as they landed on leaves for a split second. We were also surprised at the yellow water lilies that can be seen floating on its surface between June and July.

    Sitting down at one of the benches surrounding the lake for a picnic was satisfying in two ways. I was aware of the world's beauty that gave me the energy to continue up the mountain to reach the most amazing view looking over the lake. The other was to really fill myself up in order to continue the adventure adequately, full up on some snacks and refreshing water from the well.

    The hike up wasn't as hard as expected and a good path was provided with dirty rocks and slippery stones all under the shade of the tall trees. This took about an hour and a half until reaching the beautiful view of the lake and land below. Once we had taken in the astonishing views, the walk back down took another hour or so, making the hike a 3-to4-hour round trip, which was well worth it!

    Simply being back in the Black Forest and having such pleasant hikes is definitely good for the soul and I highly recommend getting yourself outside, be it in the Black Forest or anywhere outdoors. Get your intake of vitamin D and, most importantly, take in the moments that nature has to offer.

Best London walking tours

    Sandemans New London Tours

    Gain an attractive insight into London's history. Visit the City of London, stopping at St Paul's Cathedral and the Tower of London; explore East London covering Brick Lane, Cockney culture and the criminal underworld; learn about Jack the Ripper; or board on a five-venue pub crawl.

    Opening Times: Daily at 11:00 and 14:00

    City Visitor Trail

    The City Visitor Trail takes you on a journey through the heart of London. Take in famous attractions such as St. Paul's Cathedral, Guildhall, the Bank of England and the Tower of London or try the themed "side-tracks", each one moving away from the main path to give a more in-depth look at one part of the city.

    Opening Times: Available 24 hours a day, 7 days a week. Check with individual attractions for entry requirements.

    Brit Movie Tours

    Join a unique movie and TV sightseeing walking tour experience in London and go on location to see incredible sets and fascinating landmarks. Local guides provide fascinating insights into the industry and there are multiple tours available, including Doctor Who, Gangster London and Harry Potter Tour of London locations.

    Opening Times: Monday to Friday 9:00am t05:30pm

    Royal Tour of London

    Visit three royal palaces as you journey from Big Ben to Buckingham Palace and Trafalgar Square. Along the way you will discover plots to destroy Parliament, Churchill's hidden shelter, very expensive clubs for the rich and famous, and more. And if that's not enough excitement, listen closely for incredible tales of man-eating pelicans (鹈鹕)and crazy lost tourists. This walking tour is run by Strawberry Tours.

    Opening Times: The tour starts at 10am everyday.

    The earliest known copy of Leonardo da Vinci's Mona Lisa—thought to have been painted at the same time as the original masterpiece—has been discovered at the Prado Museum in Madrid, Spain. The work offers art-lovers an attractive clue to what the model for the world's most famous painting really looked like. Controllers of the museum found the picture hidden beneath layers of paints during restoration work on a picture initially thought to have been a later replica(exact copy) of the Mona Lisa.

    The restored version shows the same woman that Leonardo depicted (描画), against a landscape similar to that shown in the background of the original, which now hangs in the Louvre in Paris. And while the features of Leonardo's Mona Lisa have been dulled by centuries of dirt and layers of cracked paints—which are unlikely ever to be removed—in the recently-rediscovered copy, she appears fresher-faced and younger than her better-known "twin".

    News of the find was revealed at a meeting at London's National Gallery, linked to its "Leonardo da Vinci: Painter at the Court of Milan" exhibition. "This sensational (轰动的) find will transform our understanding of the world's most famous picture," the Art Newspaper reported, adding that the clues found on the Madrid version suggest that the original and the copy were begun at the same time and painted next to each other, as the work went on.

    Miguel Falomir, manager of Italian painting at the Prado, told reporters that expert analysis suggested a strong link between Leonardo and the artist who painted the copy. "The painting was done in the painter's own workshop," he said. "It is absolutely consistent with Leonardo's work, but Leonardo didn't actually do any work on it himself."