Bottled water has become the choice for people who are healthy and thirsty. Bottled water is all over the world. But some say the planet's health, and people's health may be suffering from it.

    The idea that bottled water is safer for humans may not be true. The Natural Resources Defense Council of America said, “There is no promise that because water comes out of a bottle, it is cleaner or safer than water from the tap.” Another New York City-based action group added that some bottled water is “really just tap water in a bottle—sometimes more clean, sometimes not.”

    It is not proven that bottled water is better than tap water. Nick Reeves from the Chartered Institution of Water and Environmental Management said, “The high mineral content(含量) of some bottled water makes them not good for feeding babies and young children.” Also, most bottled water doesn't have fluoride(氟化物), which can make teeth stronger. Kids are drinking more bottled water and less fluoridated tap water, and some say that's behind the recent rise in bad teeth.

    Storing is another problem. Placed near heat, the plastic bottles can produce bad chemicals(化学物质) into the water.

    According to the Environmental Protection Agency, some 2.7 million tons of plastic are used worldwide to bottle water each year. The plastic can take between 400 and 1,000 years to break down.

    In terms of energy use, plastic bottles are also not cheap. One report said that if water and soft drink bottlers had used 10 percent recycled materials in their plastic bottles, they would have saved about 72 million gallons of gas.

    So, if you are worried about the effect of bottled water on the Earth, you can take the following steps.

●Drink from your tap. Unless your government warns against this, it should be fine.

●Get a container(容器). Carry your tap water in a steel or a lined drinking container, and clean it between uses.

●Keep it cool. Don't drink from a bottle that has been sitting in the sun, don't store it near chemicals, and don't reuse plastic bottles.

●Choose glass containers over plastic if possible. When finished, recycle!

The National Gallery

Description：

    The National Gallery is the British national art museum built on the north side of Trafalgar Square in London. It houses a diverse collection of more than 2,300 examples of European art ranging from 13th-century religious paintings to more modern ones by Renoir and Van Gogh. The older collections of the gallery are reached through the main entrance while the more modern works in the East Wing are most easily reached from Trafalgar Square by a ground floor entrance.

Layout：

    The modern Sainsbury Wing on the western side of the building houses 13th- to 15th-century paintings, and artists include Duccio, Uccello, Van Eyck, Lippi, Mantegna, Botticelli and Memling．

    The main West Wing houses 16th-century paintings, and artists include Leonardo da Vinci, Cranach, Michelangelo, Raphael, Bruegel, Bronzino, Titan and Veronese.

    The North Wing houses 17th-century paintings, and artists include Caravaggio, Rubens, Poussin, Van Dyck, Velazquez, Claude and Vermeer．

    The East Wing houses 18th- to early 20th-century paintings, and artists include Canaletto, Goya, Turner, Constable, Renoir and Van Gogh.

Opening Hours：

    The Gallery is open every day from 10 am. to 6 pm. (Fridays 10 am. to 9 pm.) and is free, but charges apply to some special exhibitions.

Getting There：

    Nearest underground stations: Charing Cross (2-minute walk), Leicester Square (3-minute walk), Embankment (7-minute walk), and Piccadilly Circus (8-minute walk).

    To personal trainer Sammy Callari, 13-year-old Parker Seward is more than a client(客户). He's his "little brother". Over the past year, the pair have bonded. They play basketball together, share meals and dance to hip-hop like no one's watching.

    The trainer was asked to work with the 13-year-old boy, who has Down syndrome(唐氏症), because his coworker who dealt with the boy was out of town last spring. Callari had never worked with someone with a disability before. He was anxious the first day he met Parker. But Parker's big smile and cheery introduction immediately put him at ease. He reminded Callari of himself when he was a teenager. Like Parker, Callari has also faced his fair share of challenges over the years.

    As a high schooler, Callari described himself as being the weak kid. When it came to sports, he was always overlooked. His dream of playing baseball in college quickly faded away. When he went to college, Callari turned to a new sport. His younger brother trained him to become a boxer. Callari participated in five matches. Out of four of those fights he was the underdog, and he won three times. "I know how it feels," Callari said. "Society tells you that you can't do this, you can't do that." When it comes to Parker, Callari refuses to accept the word "can't".

    The friends meet twice a week to train. They bike, box, run and work on their core with push-ups. Parker has a short attention span, so it's Callari's job to keep him focused. "If Parker can do it, if he's having fun, even with his frustration, then people will ask, "Why can't I do that?" Callari said. "That's the whole task right now."

    Callari recalls Parker's mom once thanking him for taking a "chance" on her son. Callari told her he never viewed it that way. Parker may be the student, but Callari says he's also the one who's learning.

    March 21 has been declared World Sleep Day, a time to recognize and celebrate the value of sleep. Many sleep experts hope it will be a wake-up call.

    According to a poll (民意调查) by the National Sleep Foundation, nearly 4 in 5 Americans don't get as much sleep as they should during the workweek. On average, adults are thought to need at least eight hours of sleep a night, although some can manage with less and some won't do well without more. But the survey found that, on weekdays, only 21% of Americans actually get a full eight hours of sleep, and another 21% get less than six hours.

    To many of us, the thought of spending more time sleeping is, well, a big yawn. On the other hand, the thought of being smarter, thinner, healthier and more cheerful has a certain appeal. And those are just a few of the advantages that can be ours if we consistently get enough sleep, researchers say. Also on the plus side: We're likely to have better skin, better memories, better judgment, and, oh, yes, longer lives.

    “When you lose even one hour of sleep for any reason, it influences your performance the next day,” says Dr. Alon Avidan, director of the UCLA Sleep Disorders Center.

    A study published last year found the same to be true even of children. When kids aged 8 to 12 slept for just one hour less for four nights, they didn't function as well during the day.

    But sleeping has an image problem.“We see napping or sleeping as lazy,” says Jennifer Vriend, a clinical psychologist in Ottawa, Canada, and the leading author of the study with children.“We put so much emphasis on diet, nutrition and exercise. Sleep is in the back seat. In fact,”she adds,“no matter how much we work out, no matter how well we eat, we can't be in top physical shape unless we also get plenty of sleep.”

    Andrew Ritchie, inventor of the Brompton folding bicycle, once said that perfect portable bike would be "like a magic carpet... You could fold it up and put it into your pocket or handbag". Then he paused: "But you'll always be limited by the size of the wheels. And so far no one has invented a folding wheel."

It was a rare — indeed unique — occasion when I was able to put Ritchie right. A 19th-century inventor, William Henry James Grout, did in fact design a folding wheel. His bike, predictably named the Grout Portable, had a frame that was divided into two and a larger wheel that could be separated into four pieces. All the bits fitted into Grout's Wonderful Bag, a leather case.

    Grout's aim: to solve the problems of carrying a bike on a train. Now doesn't that sound familiar? Grout intended to find a way of making a bike small enough for train travel: his bike was a huge beast. And importantly, the design of early bicycles gave him an advantage: in Grout's day, tyres were solid, which made the business of dividing a wheel into four separate parts relatively simple. You couldn't do the same with a wheel fitted with a one-piece inflated(充气的) tyre.

    So, in a 21st-century environment, is the idea of the folding wheel dead? It is not. A British design engineer, Duncan Fitzsimons , has developed a wheel that can be folded into something like a slender ellipse(椭圆). From beginning to end, the tyre remains inflated.

    Will the young Fitzsimons's folding wheel make it into production? I have no idea. But his inventiveness shows two things. First, people have been saying for more than a century that bike design has reached its limit, except for gradual advances. It's as silly a concept now as it was 100 years ago: there's plenty still to go for. Second, it is in the field of folding bikes that we are seeing the most interesting inventions. You can buy a folding bike for less than £1,000 that can be knocked down so small that can be carried on a plane ——minus wheels, of course ——as hand baggage.

    Folding wheels would make all manner of things possible. Have we yet got the magic carpet of Andrew Ritchie's imagination? No. But it's progress.

Many people have long believed that bright lights draw, or attract flying insects. But that is not exactly what is going on, a new study suggests.

Researchers believe that artificial lights at night may cause problems with flying insects' natural navigation systems. As a result, the creatures fly in confusion around porch lamps, street lights and other artificial lights. "Insects have a navigational problem," said Tyson Hedrick of the University of North Carolina, Chapel Hill. He added, "They're accustomed to using light as a cue（提示）to know which way is up."

Insects do not fly directly toward a light source, but actually "tilt（倾斜）their backs toward the light," said Sam Fabian of Imperial College London. Fabian was a co-writer of the study that appeared recently in Nature Communications. This tilting action would make sense if the strongest light source was in the sky. But in the presence of artificial lights, the result is midair confusion.

For the study, researchers attached very small sensors to moths and dragonflies in a laboratory. They then filmed "motion-capture" video of flight—similar to how filmmakers attach sensors to actors to follow their movements. Researchers also used high-resolution cameras to film insects flying around lights at a field in Costa Rica. Such films permitted researchers to study in detail how dragonflies circle endlessly around light sources, positioning themselves with their backs facing the light. Researchers also documented that some insects fly upside down—and often crash land—in the presence of lights that shine straight upward like search lights. Insect flight was least disrupted by bright lights that shine straight downward, the researchers found.

"For millions of years, insects oriented themselves by sensing that the sky is light, the ground is dark—until people invented artificial lights", said Avalon Owens of Harvard University.