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.

    If you could have one superpower, What would it be ?

    Dreaming about whether you would want to read minds , see through walls , or have superhuman strength may sound silly , but it actually gets to the heart of what really matters in your life 1

    Every day in our work , we are inspired by the people we meet doing extraordinary things to improve the world.

    They have a different kind of superpower that all of us possess : the power to make a difference in the lives of others .

    We're not saying that everyone needs to contribute their lives to the poor . Your lives are busy enough doing homework , playing sports , making friends , seeking after your dreams . But we do think that you can live a more powerful life when you devote some of your time and energy to something much larger than yourself . Find an issue you are interested in and learn more . Volunteer or , if you can , contribute a little money to a cause . Whatever you do , don't be a bystander . Get involved . You may have the opportunity to make your biggest difference when you're older . But why not start now ?

    Our own experience working together on health , development , and energy the last twenty years has been one of the most rewarding parts of our lives . It has changed who we are and continues to fuel our optimism about how much the lives of the poorest people will improve in the years ahead .

    My husband Jeff and I moved into our new home in Scottsbluff last year just before Christmas. I did not have the time or energy to carry out my traditional Christmas decorating and baking activities. What was the point, anyway? It was going to be a lonely Christmas after all.

    However, the neighborly nature of west Nebraska residents started to trickle (陆续来临) in.

    There was a knock on the door one evening. It was Jeff's new colleague, John Smith, and his wife, Phyllis. The Smiths had stopped by to welcome us to town with a loaf of homemade bread. They pointed out a package on the porch (门廊). Apparently the doorbell wasn't working in the cold snowy weather and we had missed a visit from the Browns, our across-the-street neighbors, who brought us a Christmas card and more Christmas cookies.

    Then, we received an invitation to share a Christmas Eve meal with our neighbors, Ernie and Nancy Sommer, and their guest—a 90-year-old lady, who also had no family in the immediate area with whom to spend the holiday.

    I was so grateful for these gestures of welcome, especially during the holidays.

    This year, we were again unable to be with our families for Christmas. The distance and work schedules just made things too difficult. Knowing that sense of Christmas isolation all too well, we decided to try to round up some other folks who were alone in the holidays.

    Lonely people are all around us, but most of us seldom notice them. Just take a look around you. Sometimes, the smallest kind gesture can make a world of difference.

    Next time you hear a funny joke you'd better not laugh too hard. According to a paper published by the British Medical Journal, laughter isn't always the best medicine. Sometimes it can even be harmful. Professor Robin Ferner from the University of Birmingham, one of the authors of the study, found that bad things could happen to people who laughed too much. He says, "We found people with heartbeat problems which had stopped their hearts, we found people who had fainted(昏倒), and we found people who'd dislocated their jaws or burst their lungs."

    It seems that laughing can be no laughing matter. But it's not all doom and gloom. Professor Ferner says there are benefits to laughing when you want to lose weight, for example. Yes, that's right: laugh and be slimmer! Professor Ferner explains that: "You use energy when you laugh, you move your diaphragm(横隔膜), you expand your lungs, and both those things can be helpful."

    According to the research, laughing for a quarter of an hour can burn 40 calories, and if you laughed all day you'd use about 2, 000 calories, which is what most people consume in a day. But don't do that or you might end up with a painful jaw. Ouch! Or you might find people looking at you in a funny way.

    But I don't want to finish this article leaving you feeling desperate. Laughter comes naturally for most of us. Babies begin to laugh at around 3-6 months. So give in to your sense of humour and keep smiling. Life is short anyway.

    In its early history, Chicago had floods frequently, especially in the spring, making the streets so muddy that people, horses, and carts got stuck. An old joke that was popular at the time went something like this：A man is stuck up to his waist in a muddy Chicago street. Asked if he needs help, he replies, "No, thanks. I've got a good horse under me."

    The city planner decided to build an underground drainage （排水） system, but there simply wasn't enough difference between the height of the ground level and the water level. The only two options were to lower the Chicago River or raise the city.

    An engineer named Ellis Chesbrough convinced the city that it had no choice but to build the pipes above ground and then cover them with dirt. This raised the level of the city's streets by as much as 12 feet.

    This of course created a new problem: dirt practically buried the first floors of every building in Chicago. Building owners were faced with a choice: either change the first floors of their buildings into basements, and the second stories into main floors, or hoist the entire buildings to meet the new street level. Small wood-frame buildings could be lifted fairly easily. But what about large, heavy structures like Tremont Hotel, which was a six-story brick building?

    That's where George Pullman came in. He had developed some house-moving skills successfully. To lift a big structure like the Tremont Hotel, Pullman would place thousands of jackscrews （螺旋千斤顶） beneath the building's foundation. One man was assigned to operate each section of roughly 10jackscrews.At Pullman's signal each man tured his jackscrew the same amount at the same time, thereby raising the building slowly and evenly. Astonishingly, the Tremont Hotel stay open during the entire operation, and many of its guests didn't even notice anything was happening.

    Some people like to say that every problem has a solution. But in Chicago's early history, every engineering solution seemed to create a new problem. Now that Chicago's waste water was draining efficiently into the Chicago River, the city's next step was to clean the polluted river.

    The Taj Mahal, in Agra, India, is one of the most brilliant structures on Earth. It is nearly 400 years old. Emperor Shah Jahan had it built in memory of his wife. It took about 20 years to build the monument. Some 20,000 workers and 1,000 elephants helped get the job done. Today, the Taj Mahal is not just a symbol of cultural history. It's also India's most famous tourist attraction. About 8 million people visit it each year.

    But pollution is turning the white marble monument shades of green, yellow, and brown. The Taj Mahal stands on the polluted Yamuna River. Insects are attracted to the dirty water. They leave greenish droppings on the building. Air pollution is also a big threat. Factories and cars release pollution into the air. It sticks to the Taj Mahal's suidEace. In the 1990s, India's Supreme Court ordered hundreds of factories near the monument to close. Also, car and bus traffic was restricted. From time to time, workers clean the Taj Mahal. But doing so is difficult, expensive, and time-consuming. And it doesn't prevent the discoloration.

    On July 11, India's Supreme Court gave the city of Agra a warning: "Either you destroy the Taj Mahal or you restore it". Authorities in the city submitted a draft of an action plan on July 24. It suggests banning plastics and construction from the area. It also calls for the closing of more factories.

    "In order to preserve the Taj Mahal, people must come together to work toward a solution. There needs to be positive pressure on people to act. We need to act immediately," Sachchida Tripathi says. He worked on a 2014 study of pollution at the Taj Mahal. "We are trying," he adds, "but we need to try more."