Bamboo is one of the nature's most surprising plants. Many people call this plant a tree, but it is a kind of grass.

    Like other kinds of grass, a bamboo plant may be cut very low to the ground, but it will grow back very quickly. A Japanese scientist recorded one bamboo plant that grew almost 1.5 meters in 24 hours! Bamboo grows almost everywhere in the world except Europe. There are more than 1,000 kinds of bamboo that grow around the world on both mountains and plains(平原).

    Not all bamboo looks the same. Some bamboo plants are very thin. They may only grow to be a few centimeters wide while others may grow to more than 30 centimeters across. This plant also comes in different colors, from yellow to black to green.

    Many Asian countries have been using bamboo for hundreds of years. They often use bamboo for building new buildings. As a matter of fact, the cables(绳索) that hold up the hanging bridge across the Min River in Sichuan are made of bamboo. The bridge has been in use for more than 1,000 years, and is still holding strong.

    In Africa, engineers are teaching poor farmers how to find water using bamboo. These African countries need cheap ways to find water because they have no money, and their fields often die from no rain and no water. It seems that bamboo is one of the best things they can use. Bamboo pipes and drills(钻) can help to make the poor thirsty fields to be watered.

    Having good etiquette(礼节，礼仪) at the workplace is very important to be a favorite in an office. However, many people aren't aware of the workplace etiquette and this creates a very bad impression in the office. So it's important to know some workplace etiquette tips.

    Among all the workplace etiquette guidelines, the most important is to be punctual(准时的) to your office. Though going late due to an emergency is okay, habitual late comers are never appreciated in any organization. By arriving at your office on time, you show that you're aware of your responsibilities and have respect for the organization. In case you feel that you would be late, call the concerned authority and report the matter to him or her.

    Also, a proper knowledge of the workplace email etiquette is a must. In the official emails, you need to mention the subject concisely (简洁地), while at the same time include all the important details which are to be shared. You should use good and grammatically correct language while writing emails.

    A knowledge of telephone etiquette in the workplace is very important as well. While talking on the telephone, be polite and listen to what they're saying carefully. Only then should you say what you feel. Speak in a voice which would be heard clearly at the other end.

    The workplace guidelines are important even while you're dining or celebrating with your co-workers. If you get a call in between, receive it after you're permitted by the others by saying "excuse me". Don't talk loudly while eating. Greet people well and try to make them feel comfortable, while being in your company.

    These guidelines will help you become the best employee of a company. All the best!

    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."

Dear Mary,

    How are you? I saw you posted some wonderful photos of the coastline near your hometown. You're really getting into your photography! Right now I'm taking a break from social media (媒体) to write you an email.

    Remember you said you'd like to come over to the UK sometime this year? Well, I was thinking that this year you might like to come to the Edinburgh Festival with me in August. I've got an aunt with a flat in the city centre who could put us up.

    Do you know much about the festival? It's very famous — the biggest, most popular arts festival in the world! There are lots of things going on — art exhibitions (展览), concerts of all kinds, modern dance, a book festival, etc. The thing it's most famous for is the newest and most exciting theatre. People come from all over the world and perform (表演) in their own language.

    In Scotland you have the best of both worlds: culture and wild land. After the festival, we could hire (租) a car and go up to some of the islands off the west coast, like Skye. The weather can be changeable in August, but the landscape (风景) is beautiful, with empty beaches and rocky mountains. It's the perfect place for you to take photos. Afterwards, we could head back to the east coast and visit my friend Rob in St. Andrews. It's really pretty and Rob's enjoyable to be with. You'd get on well with him.

    So, why don't you have a think about it and then get back to me? Take your time, there's no rush.

    Speak to you soon.

    Race walking shares many fitness benefits with running, research shows, while most likely contributing to fewer injuries. It does, however, have its own problem.

    Race walkers are conditioned athletes. The longest track and field event at the Summer Olympics is the 50-kilometer race walk, which is about five miles longer than the marathon. But the sport's rules require that a race walker's knees stay straight through most of the leg swing and one foot remain in contact (接触) with the ground at all times. It's this strange form that makes race walking such an attractive activity, however, says Jaclyn Norberg, an assistant professor of exercise science at Salem State University in Salem, Mass.

    Like running, race walking is physically demanding, she says, According to most calculations, race walkers moving at a pace of six miles per hour would burn about 800 calories(卡路里) per hour, which is approximately twice as many as they would burn walking, although fewer than running, which would probably burn about 1,000 or more calories per hour.

    However, race walking does not pound the body as much as running does, Dr. Norberg says. According to her research, runners hit the ground with as much as four times their body weight per step, while race walkers, who do not leave the ground, create only about 1.4 times their body weight with each step.

    As a result, she says, some of the injuries associated with running, such as runner's knee, are uncommon among race walkers. But the sport's strange form does place considerable stress on the ankles and hips, so people with a history of such injuries might want to be cautious in adopting the sport. In fact, anyone wishing to try race walking should probably first consult a coach or experienced racer to learn proper technique, she says. It takes some practice.