Probably no other musical instrument is as popular as the guitar around the world. Musicians use the guitar for almost all kinds of music. Country and western music would not be the same without a guitar. The traditional Spanish folk music called Flamenco could not exist without a guitar. The sound of American blues music would not be the same without the sad cry of the guitar. And rock and roll music would almost be impossible without this instrument.

    Music experts do not agree about where the guitar was first played. Most agree it is ancient. Some experts say an instrument very much like a guitar was played in Egypt more than 1,000 years ago. Most experts say that the ancestor of the modern guitar was brought to Spain from Persia sometime in the 12^th century. The guitar continued to develop in Spain. In the 1700s it became similar to the instrument we know today.

    Many famous musicians played the instrument. The famous Italian violins Niccole Paganism played and wrote music for the guitar in the early 1800s. Franz Schubert used the guitar to write some of his famous works. In modern times Spanish guitarist Andres Segovia helped make the instrument extremely popular.

    In the 1930s, Les Paul began experimenting to make an electric guitar. He invented the solid-bodied electric guitar in 1946. The Gibson Guitar Company began producing its famous Les Paul Guitar in 1952. It became a powerful influence on popular music. The instrument has the same shape and the same six strings (弦) as the traditional guitar, but it sounds very different. Les Paul produced a series of extremely popular recordings that introduced the public to this music. Listen to this Les Paul recording. It was the fifth most popular song in the United States in 1952. It is called “Meet Mister Callaghan.”

    How Did the Ancient Chinese Keep Food Warm in Winter?

    Facilities like electric rice cookers, microwaves, and electric kettles, make it easy for people to keep food warm and enjoy a comfortable winter. So how did Chinese people in ancient times keep food warm in winter without these? In fact, ancient Chinese people used their own methods of heat preservation as early as the Shang and Zhou Dynasties.

    ☆ “Wen Ding”, ancient rice cooker

    One of the major functions of an electric rice cooker is to keep food warm. The “Wen Ding”, an ancient cooking container, served the same purpose, but instead of using electric energy, the ancient cooking container preserved heat by burning fuels like charcoal.

    The “Wen Ding” unearthed in Nanjing in 1989 is thought to be the oldest of its kind discovered in China, dating back to the Stone Age. The craftsmanship of making the “Wen Ding” was developed in the Bronze Age. The bronze Ding from the Shang and Zhou Dynasties took on different shapes and structures.

    ☆ “Ran Lu”, ancient small hot pot

    The “Ran Lu” is a small size cooking vessel (器皿) made of bronze, which can be divided into three parts. A charcoal stove forms the main structure, with a bottom tray to hold charcoal ashes, and a movable cup at the top. Some experts have concluded that the vessel's structure suggests it may have been used as a small hot pot and that these vessels became popular in the Warring States Period (475—221 B.C.).

    ☆ Bronze You, ancient kettle

    The Bronze You was one of the most common wine containers during the Shang and Zhou Dynasties. The Bronze You can also be used to warm wine. For example, the Bronze You with beast mask design, unearthed in Jiangxi Province, has an opening where charcoal could be placed. Just as people today can't do without an electric kettle, the Bronze You allowed people to enjoy a hot drink.

    ☆ Bronze Yan, ancient steamer

    Although the “Wen Ding” was effective at keeping food warm, the ancient Chinese people later found that its burning process produced pollution. As a result, the Bronze Yan made with a two-tier structure and used to steam rice and other grains. After the Eastern Han Dynasty (25A.D.-220A.D.), further improvements to the Bronze Yan led to the modern-day steamer.

    A young woman sits alone in a café sipping tea and reading a book. She pauses briefly to write in a nearby notepad before showing her words to a passing café waiter: "Where are the toilets please?" This is a familiar scene in Tokyo's so-called "silent cafés", where customers are not allowed to speak, and only communicate by writing in notepads.

    The concept rises by a desire to be alone among young Japanese, a situation brought by economic uncertainty, a shift in traditional family support structures and the growing social isolation. The phenomenon is not limited to coffee shops but covers everything from silent discos, where participants dance alone wearing wireless headphones connected to the DJ, to products such as small desk tents designed for conversation-free privacy in the office. One Kyoto company even offers single women the opportunity to have a "one woman wedding"—a full bridal affair, complete with white dress and ceremony, and the only thing missing is the groom. The trend has its own media expression-“botchi-zoku”, referring to individuals who consciously choose to do things completely on their own.

    One recent weekday afternoon, Chihiro Higashikokubaru, a 23-year-old nurse, travelled 90 minutes from her home, to Tokyo on her day off in order to enjoy some solo time. Speaking quietly at the entrance of the cafe, Miss Higashikokubaru said: “I heard about this place via Twitter and I like the idea of coming here. I work as a nurse and it's always very busy. There are very few quiet places in Tokyo, and it's a big busy city. I just want to come and sit somewhere quietly on my own. I'm going to drink a cup of tea and maybe do some drawings. I like the idea of a quiet, calm atmosphere.”

    The desire to be isolated is not a new concept in Japan, home to an estimated 3.6 million "hikikomori" - a more extreme example of social recluses(隐士) who withdraw completely from society.

    Are you a social media addict? Are you always checking your smart phone to see how many "likes" you've received for your latest post? Maybe you feel comforted by the sound that someone has sent you a message?

    Don't worry, you're not alone. We check our phones an average of 150 times a day, and around 30% of the total time spent online is devoted to social media. Some experts now fear this habit could be damaging our mental health.

    This is something particularly bothering young adults, according to a study from the University of Pittsburgh. It found the more they used social media, the more likely they were to be depressed. In tests, those people who checked social media frequently were 2.7 times more likely to be depressed compared to those who spent most of their time generally surfing the Internet, who had just 1.7 times the risk.

    Some of us certainly feel sad when we're ignored on social media sites, or when we see someone else having a better time than us. But depression is a more serious condition and clinical psychologist, Abigael San, recently told the BBC that ,"It's a real issue, and it's been getting significantly worse over the last 5﹣6 years. You can get so hooked that it takes you away from your real relationships. "However, Abigael does admit that social media is more likely to worsen pre﹣existing issues than directly cause them.

    Other research by the University of Glasgow found that teenagers are affected by the 24﹣hour demands of their social media accounts. It found that those with higher levels of emotional investment in social media, and who use it at night, were more likely to feel depressed and anxious.

    Despite these warning signs, why do some of us continue to keep clicking? Well, I suppose we all want to be liked and we don't want to miss out on a conversation that's taking place online. But we need to know when to switch off our virtual online world and connect with the real world instead.

    Being able to land safely is a critically important skill for all flying animals. Whereas terrestrial animals face no particular challenge when they need to stop running or crawling, flying animals move at much higher speeds, and they must be careful about how they land. Hitting the ground, or even water, at full flight speed would be quite dangerous. Before touching down, they must decrease their speed in order to land safely. Both bats and birds have mastered the skill of landing, but these two types of flyers go about it quite differently.

    In the past it was believed that, in terms of flying mechanics, there was little difference between bats and birds. This belief was based only on assumption, however, because for years nobody had actually studied in detail how bats move their wings. In recent years, though, researchers have discovered a number of interesting facts about bat flight. Bats are built differently from birds, and their wings incorporate(结合) both their front and hind limbs (后肢). This makes their limbs working together more difficult for bats and, as a result, they are not very good at flying over longer distances. However, a bat can quickly change its direction of flight or completely reverse it, something a bird cannot easily do.

    Another interesting characteristic of bat flight is the way in which bats land—upside down! Unlike birds, which touch down on the ground or on tree branches, bats can be observed flying around and then suddenly hanging upside down from an object overhead. How do they do it? A group of researchers recently used video cameras to film bats landing on nets suspended from the ceiling of their laboratory and studied the recordings in slow motion. They painted spots on the bats' wings to see in detail what happens to the wings in flight and during touchdown. It turns out that the bats flew in a straight line up to the net and then quickly flipped over and attached themselves to it upside down. One disadvantage to this landing routine is that the bats often slam into their landing spot with some force, which probably causes pain. However, not all bats hit their landing spots with the same speed and force; these will vary depending on the area where a bat species makes its home. For example, a cave bat, which regularly rests on a hard stone ceiling, is more careful about its landing preparation than a bat more accustomed to landing in leafy treetops.

    The following are four famous malls in the world where you can not only purchase things but also enjoy entertainment.

    Mall of America (Minnesota, USA)

    This Mall has a theme park and a wedding church, where more than 5,000 couples have been married since its opening. The mall of America opened in 1992 and is the third largest mall in North America.

    The mall of America is the most visited shopping mall in the world, with more than 40 million visitors annually. Spending 10 minutes in every store would take shopper more than 86 hours to complete their visit to the Mall of America.

    Mall of the Emirates (Dubai)

    The mall of the Emirates is an entertainment and shopping resort located in Dubai. It offers a full range of shopping, leisure and entertainment facilities.

    This shopping center is home to over 450 retailers（零售商）and also features a complete range of entertainment options, including Ski Dubai, the first indoor ski destination in the middle East.

    West Edmonton Mall (Alberta, Canada)

    The fifth largest mall in the world and the largest in North America, it has the largest indoor water park, which has the biggest wave pool in the world.

    The mall has a theme park called Galaxyland, with a number of attractions, including a roller coaster. In addition, the mall has an indoor lake, which is home to four sea lions.

    The Dubai Mall (Dubai)

    The Dubai Mall is the world's largest mall in total area.

    The mall has 1,200 shops and houses an aquarium（水族馆）which earned the Guinness World Record for the world's "largest Acrylic Panel". The mall is also home to an ice rink（溜冰场）, a 250-room luxury hotel and 22 cinema screens, plus 120 restaurants and cafes. It's also famous for the unique "malls-within-a-mall" concept, with themed shopping area like Gold Souk, Fashion Island and The Grove, an indoor-outdoor streetscape with a fully retractable（可缩回的）roof.