A 17-year-old boy, caught sending text messages in class, was recently sent to the vice principal's office at Millwood High School in Halifax, Nova Scotia. The vice principal, Steve Gallagher, told the boy he needed to focus on the teacher, not his cellphone. The boy listened politely and nodded, and that's when Mr. Gallagher noticed the student's fingers moving on his lap. He was texting while being scolded for texting. “It was a subconscious act,” says Mr. Gallagher, who took the phone away. “Young people today are connected socially from the moment they open their eyes in the morning until they close their eyes at night. It's compulsive.”

    A study this year by psychology students at Covenant College in Lookout Mountain, Ga., found that the more time young people spend on Facebook, the more likely they are to have lower grades and weaker study habits. Heavy Facebook users show signs of being more sociable, but they are also more likely to be anxious, hostile or depressed. (Doctors, meanwhile, are now blaming addictions to 'night texting' for disturbing the sleep patterns of teens.)

    Almost a quarter of today's teens check Facebook more than 10 times a day, according to a 2009 survey by Common Sense Media, a nonprofit group that monitors media's impact on families. Will these young people get rid of this habit once they enter the work force, or will employers come to see texting and 'social-network checking' as accepted parts of the workday?

    Think back. When today's older workers were in their 20s, they might have taken a break on the job to call friends and make after-work plans. In those earlier eras, companies discouraged non-business-related calls, and someone who made personal calls all day risked being fired. It was impossible to imagine the constant back-and-forth texting that defines interactions among young people today.

    Educators are also being asked by parents, students and educational strategists to reconsider their rules. “In past generations, students got in trouble for passing notes in class. Now students are skilled at texting with their phones still in their pockets,” says 40-year-old Mr. Gallagher, the vice principal, “and they're able to communicate with someone one floor down and three rows over. Students are just fundamentally different today. They will take suspensions rather than give up their phones.”

    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.”

    Golden Gate Bridge

    Located in San Francisco,the Golden Gate Bridge started in the year 1933 to connect the San Francisco Peninsula with Marin County.It was finally thrown open to public traffic in 1937.It cost $25.7 million in the construction.Till the year 1957,the Golden Gate Bridge,at a length of 2,737 meters,was the longest suspension bridge in the world.

    Brooklyn Bridge

    The Brooklyn Bridge is located in Brooklyn.It is one of the oldest suspension bridges in the United States, having been opened in the year 1883.The length of the bridge is 1,843 meters.The bridge has been featured in several Hollywood movies.

    George Washington Bridge

    Also known as the Hudson River Bridge and the Columbus Bridge,the George Washington Bridge which connects Fort Lee to Manhattan came into use in 1931 after a construction period of almost 4 years.It is a two level suspension bridge that cost about $52 million to build.

    Mackinac Bridge

    This is the third biggest suspension bridge in the world at a length of 8,038 meters.The architect of this bridge was Dr.David B. Steinman who directed the construction of the bridge which started in the year 1054 and opened to the public in 1958.People using this bridge are charged a certain amount of money.

    Navajo Bridge

    Located in Arizona,this bridge crosses the Colorado River and is almost 250 meters long.The construction of this bridge started in the year 1927,ending two years later,costing $390,000.In the 1990s a second bridge was built which was opened to the public in 1994.The first bridge is now used only by pedestrians.

    Everybody hates rats (big mice). But in the earthquake capitals of the world — Japan, Los Angeles, Turkey — rats will soon be man's best friends.

    What happens after an earthquake? We send in rescue dogs. Why? Because they can smell people. Dogs save lives. They help rescuers to find living people. But dogs are big and they can't get into small spaces. So now a new research project is using a smaller animal to save lives: the rat.

    How does it work? First, the rat is trained to smell people. When this happens, the rat's brain gives a signal (信号)．This is sent to a small radio on its back, and then the rescuers follow the radio signals. When the rat's brain activity jumps, the rescuers know that someone is alive. The rat has smelled that person.

    Although there are already robots which can do this job, rats are better. Christian Linster at Cornell University, New York, says, "Robots' noses don't work well when there are other smells around. Rats are good at that." Rats can also see in the dark. They are cheaper and quicker to train than dogs, and unlike robots, they don't need electricity!

    The "rat project" is not finished, but Julie Ryan of International Rescue Organization in Scotland says, "It would be wonderful. A rat could get into spaces we couldn't get to, and a rat would get out if it wasn't safe." Perhaps for the first time in history, people will be happy to see a rat in a building (but only after an earthquake, of course).

    Charles Darwin lived an unusually quiet life. In 1842, Darwin and his wife Emma moved from London to Kent in southern England to have as little disturbance (烦扰) as possible. They already had two children then, and would go on to have eight more in the country.

    Darwin had very regular (有规律的) habits. He rose early and went for a walk. After breakfast he worked in his study until 9：30 am, his most productive time of the day, and then read his letters lying on the sofa before returning to work.

    At midday he would go for another walk with his dog, stopping at his greenhouse to inspect (查看) his experiments. Then he would go for another walk around an area of woodland. While walking on his "thinking path", Darwin would consider his unsolved scientific problems.

    After lunch he read the newspaper and wrote letters. His network of friends provided information from all corners of the world.

    The Darwins were not very strict parents and the children were always seen running wild. Their father worked patiently to a background of playful shouts and little footsteps walking past his study door.

After dinner Darwin played backgammon (a game for two people to play) with his wife. He once wrote, "Now the result with my wife in backgammon stands like this: she... has won only 2,490 games, while I have won, hurrah (a cheer of joy or victory), hurrah, 2,795 games!"

    Although he had poor health, Darwin continued to publish (出版)a lot of creative works until his final book in 1881. He died the following year, aged 73.

    Rather than a quiet space in the local churchyard, which he called "the sweetest place on Earth", Darwin was given a state funeral (国葬) in London's Westminster Abbey.

    When we are young we are taught that it's wrong to lie and we should always tell the truth. Unfortunately, most children lie even if they're told not to. Research carried out at the Institute of Child Study at Toronto University has shown that this might not be such a bad thing. Apparently (显然地), children who tell lies when they're two years old have a good chance of becoming successful adults (成年人).

    According to the research, at the age of two, 20 percent of children lie. At the age of three, 50 percent lie, and at four almost 90 percent lie. By the age of 12 almost every child tells lies.

    Lying needs much brain work. And the better the lie is, the more work the brain has to do. By training the brain early, researchers believe children will be able to think more clearly when they are adults.

    Recent research, carried out by the Science Museum in London, has shown some interesting facts about the way we lie as adults. According to the research, the average British man tells three lies every day, that's over 1,000 lies a year. However, the average woman apparently only lies twice a day.

    Most people think women are better liars (说谎者) than men although in fact they tell fewer lies. Popular women's lies include 'Nothing's wrong, I'm fine', 'I don't know where it is, I haven't touched it', and 'It wasn't that expensive'.

    Some people say you can lie as long as it's a white lie. A white lie is a lie told to avoid hurting someone's feelings. One of the most common lies for both men and women is 'It's just what I've always wanted', said after opening a present from their partner.