Recently, online hike-sharing has become the new favorite in China. In major cities, bikes in, yellow, orange, blue, white and green, can be seen almost everywhere on the street. It seems that these bikes appeared suddenly, adding a new beautiful scenery to Chinese cities.

    Both the market and the public welcome online bike-sharing, but is it really a promising business? Well, it depends. After all, online bike-sharing platforms can never get away with huge operating cost and uncertain government policy.

    Some theorists might say that online bike-sharing platforms can earn a fortune simply through deposit. Since users will always need to rent bikes, their deposit will always be kept to online bike-sharing platforms.

    However，although online bike-sharing platforms may be able to use the deposit for other purposes at the primary stage, they will have to set up a special account, so that the deposit shall be used specially for its designated (指定的) purpose. As the market gets increasingly mature, they will have to do so whether to be responsible for users or in consideration of possible government regulations.

    Now that online hike-sharing platforms can，t make profit through deposit，how can they become profitable as fiercer market unfolds? Although Hu Weiwei, CEO of Mobike, stated in an article that she would take Mobike as charitable(慈善的) project if she failed, running a startup is absolutely different from managing a charity organization. After all , she has to pay back investors' billions of investment(投资).

    To make profit, online bike-sharing platforms might have toincrease rent fee for each trip, just as Didi did

    From this aspect, it might be a really good business. If we consider full screen ads fee, recommendation fee for business owners, etc. , its annual income might reach at least RMB 15 billion. If we consider the huge operation cost, including bike repairs，bikes' service life and labor cost, there might not be much net profit left. After all, offline operation cost has always been an unbearable burden for such internet plus mode-based startups.

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    Although Paris is often considered the city of romance, close to a million adult who call it home are single. Many single people say that France's capital is one of the most difficult places to meet people. The complaints of this lonely group have inspired a new phenomenon known as “supermarket dating.” At Galerie Lafayette Gourmet, singles can shop for more than just the items on their grocery list. They can look for someone who has blue eyes, brown hair, and is 1.8 meters tall, or whatever may be on their romantic shopping list.

    At this Paris location, single people of all ages can schedule their shopping for Thursday nights between 6:30 and 9:00 p.m. When they walk through the door, they pick up a purple basket to advise that they are looking for love. They try to arrive early because the baskets disappear quickly, and then they have to wait in line for their turn to wander the store aisles.

    With purple baskets in hand, shoppers can consider their romantic options while they pick out their groceries. When they are ready to pay, they can go to the checkout line for singles who want to chat.

    Most of the people who look for love in the supermarket are skeptical of Internet dating. They know that it is easy to embellish（美化）one's appearance or to lie about one's age over the Internet. The supermarket, on the other hand, is considered a safe and casual environment in which to meet a potential match. In addition, what one finds in another's grocery basket can say a thing or two about that person's character or intentions. Buying pet food can be a man's way of showing a potential match that he has a sensitive side. Women who fill their baskets with low-fat food show their healthy style of living. These days it's possible to find much more than food at a grocery store.

    Simone was born in Ohio, but grew up in Texas. Early on, she and her siblings (兄妹) were adopted by her grandparents, who she says support her in everything. She first realized she wanted to be a gymnast at the age of 6 when she and her classmates went on a field trip to a local gym. A coach at the gym saw her natural talent and wrote a letter to her grandparents urging them to get her involved. The sport she signed up for “for fun” soon turned into her life's enthusiasm.

    Simone is energetic, so it's no surprise that she's got a few medals in her time. Her ten world gold medals are the most ever achieved by a woman in gymnastics history. She is also the first woman to win four medals at the same World Championships, which happened in her second year performing in 2014.

In 2015 Simone became the first gymnast to win three constant all-around titles at the World Gymnastic Championships. She even amazed herself, telling the interviewer “I blew my own mind.” and posting to social media “breaking history is kind of cool.”

    What surprised everyone most though, was that she was performing perfectly as she usually does—her skill is so beyond everyone else that she can't be beaten even when she trips up!

    Climate change will force exhausted birds migrating to Europe from Africa to travel further, with possibly disastrous consequences, according to a study.

    The annual voyage of some species, which fly north in search of food and suitable habitats, could increase by as much as 400 kilometers (250 miles), the research found. “Marathon migrations for some birds are set to become even longer,” said Stephen Willis, a professor at Durham University in Britain and the main architect of the study. “This is bad news for birds like the White throat, a common farmland bird. The added distance is a considerable threat. As temperatures rise and habitats change, birds will face their biggest challenge since the Pleistocene era (更新世), which ended 11,000 years ago,” he said in a statement.

    Some 500 million birds migrate each year from Africa, some weighing as little as nine grams (three-tenths of an ounce). To complete a voyage that can be thousands of kilometers long, birds have to fatten themselves up to twice their normal weight. Some even shrink their internal organs (收缩内脏) to become more fuel efficient, so any additional distance may be dangerous.

    The study finds that from 2007 to 2010, nine out of 17 species examined are going to face longer migrations, particularly birds that cross the Sahara Desert. Some birds travel the Sahara and the Mediterranean Sea in a one go, while others have a break in northern Africa before crossing. Many fly at night, when temperatures are cooler.

    A few — such as the Blackcap — have started to adapt by spending winters in Britain, but such behavior remains exceptional, the study said. The study forecasts that the migration distance of the Orphean Warbler will jump from 2,700 kilometers (1,700 miles) to between 3,050 and 3,350 kilometers (1,900 and 2,100 miles), with even longer increases for the Subalpine and Barred Warblers.

Hidden London: the city's lesser-known delights Dulwich Picture Gallery

    As much an excuse to enjoy the village charm of Dulwich Village as to admire some delicate European masterworks,  this gallery is a southeast London charmer,  which was founded in 1811. Join a free guided tour to the permanent collection (3 pm Saturday and Sunday), catch the latest temporary exhibition and admire the lovely garden (open 1: 30 pm to 3: 30 pm Tuesdays).

Where: Gallery Rd SE21 7AD

Train: West Dulwich

Temple Church

    Featuring in the novel TheDaVinciCode and dating back to the late 12th century,  this is one of London's oldest and holiest medieval (中世纪的) treasures. Built by the Knights Templar,  the church is divided into the Round—which contains the statues of crusading knights,  who tried to recover the Holy Land from the Muslims in the Middle Ages—and the Chancel,  where the priests (牧师) and singers performing in church services sit.

Where: Temple EC4Y 7DE

Underground: Temple or Blackfriars

Chelsea Physic Garden

    Endlessly satisfying the green-fingered, the plain curious or those eager to discover botanical interests in central London, this delightful walled garden was founded by the Apothecaries' Society in the 17th century and is one of the oldest botanical gardens in London.

Where: 66 Royal Hospital Rd SW3 4HS

Underground: Sloane Square

Estorick Collection of Modern Italian Art

    Built between 1953 and 1958, the Estorick is Britain's only gallery devoted to Italian art. It draws together a fascinating collection of Futurist masterpieces from Umberto Boccioni, Giacomo Balla, Carlo Carra and others, who emphasized the importance of modern things, especially technology and machines.

Where: 39a Canonbury Sq N1 2AN

Underground: Highbury or Islington

    Almost every second of every day an older adult falls in the United States. That's approximately 29 million falls per year and nearly 27, 000 deaths, according to the Centers for Disease Control and Prevention.

    Still in the stating stage, the Active Pelvis Orthosis (APO) system in Switzerland wants to make a lightweight, wearable exoskeleton (外骨骼) that could detect signs of balance loss and assist with balance recovery to keep the elderly wearer from falling, only when needed.

    Other exoskeletons, either in development or on the market today, assist with movement and make heavy objects feel lighter. Mobility-impaired people can walk again. But none of these devices predict what the wearer is going to do next and take measures to correct an unsteady move.

    The 3 kilogram (6.7 pound) exoskeleton was built entirely from scratch by the research team and is designed to be worn on the lower half of the body. A waistband connects to two movable carbon fiber braces (支架), each one positioned on the outer side of a leg. Tiny motors and so-called "adaptive oscillators" (适配振荡器) in the computer circuits use a special process to detect the, wearer's unique paces. That part takes just a few minutes.

    While wearing the exoskeleton, a person may feel the braces and the motors pushing slightly on their legs. If their paces go against normal, the motors create a force in the braces that cause them to stiffen up and push a little more strongly against the legs, which provides stability.

    In the next three years, the APO hopes to develop something that is commercially available.