The United States is a country of immigrants. It is a place where people from all over the world come to build a better life. Some immigrants bring their families. Some bring a few of their favorite things. Others come alone with nothing but determination. One thing that every immigrant brings with them is their culture.

    American immigration began in 1607 with the colony (殖民地) of Jamestown. In 1620, another group of people left England to build a settlement in America. They wanted to go to a place where they could practice their religion freely. Then many more people left their homes in Europe to build a better life in America. Many also came to America from Africa. By 1770, more than two million people had moved to America. Later on, more people came to the United States than ever before.

    In cities all over America, you can see different cultures that formed this country. Many things that you may think of as being “American” are actually from a foreign culture. Some of the best examples of this are the foods people eat. Pizza and spaghetti are foods that all Americans know and love. But both of them are from Italy. Baseball is an all-American sport. But the hot dogs that people eat during the game are a type of food that was brought to America by German immigrants.

    Over time, pizza and hot dogs have become a part of what is considered to be American food. In the same way, different groups of people have come together to define what an American is. An American can be a person of any background. An American can be of any faith. An American can be of any skin color. They can speak English clearly. They can speak English with an accent. Each new immigrant adds something new to American culture. It will keep changing as more people come to this country.

    “One thing I enjoy about my job is that I can work on something that is actually active,” says Game McGimsey, an American volcanologist(火山学家). Part of his job includes keeping an eye on Alaska's many active volcanoes and giving people a heads-up when a volcano might erupt(喷发).

    Like most jobs in the science, volcanology requires a lot of education. McGimsey received an undergraduate degree in geology at the University of North Carolina, then landed an internship(实习期) with a geologist at the USGS(美国地质勘探局) whose work field was about volcanoes. After earning a graduate degree at the University of Colorado, McGimsey accepted a job with the USGS and has been with the Alaska Volcano Observatory for 25 years.

    Volcanoes can influence the world in ways we might not think about. For example, on Dec.15 1989, a 747 jetliner (a large airplane) flew through a thick ash cloud produced by Mount Redoubt, an Alaskan volcano that hadn't erupted in 25 years. The ash caused all four engines to die, and the plane's electronics went dead.

    “The plane was within several thousand feet of flying into the mountains below when the pilots got a couple of engines restarted and landed safely in Anchorage,” McGimsey says. It cost nearly $80 million to repair the damage to the plane.

    Such situations show just how dangerous volcanoes can be. However, volcanologists know the risks and are prepared to protect themselves.

    McGimsey admits, “There is certainly a higher danger level in volcanology than some other jobs. We understand how serious the danger is, and we don't like taking unnecessary chances. We avoid getting too close to an erupting volcano, because it is not worth injury or death simply to get a rock or a photograph.”

    Driving in Canada is similar to driving in many parts of the United States. Distances and speeds, however, are posted in kilometers per hour and some signs, particularly in Quebec, may only be in French.

    Unless otherwise posted, the maximum (最大限度的) speed limit in Canada is 50km/hr in cities and 80km/hr on highways. On rural highways, the posted speed limit may be 100km/hr. It is illegal to take automobile radar detectors (汽车雷达检测器) into Quebec, Ontario, Manitoba, and the Yukon. Seat belt use is required by law for all passengers, and child car seats must be used by children under 40 pounds. Some provinces require drivers to keep their vehicles' headlights on during the day and some have banned (禁止) driving while using a hand-held cell phone. Motorcycles cannot share a lane (车道), and safety helmets for motorcycle riders and passengers are necessary. Running a red light is a serious crime throughout Canada and drivers are advised to stop before starting when a light turns green.

    Winter travel can be dangerous due to heavy snowfalls and icy conditions. Some roads and bridges are often closed in winter. Snow tires are required in some provinces. Travelers should also be careful about animals while driving at night in rural areas.

    Highway 401, from Detroit to Montreal, is one of the busiest highways in North America. It has been the scene of many deadly traffic accidents due to sudden and severe weather changes, high rates of speed, and heavy truck traffic. Thus drivers should be alert while travelling here.

    Please refer to our Road Safety page for more information. Also, we suggest that you visit the website of Canada's national authority responsible for road safety.

    London's newest skyscraper(摩天大楼)is called the Shard and it cost about 430 million pounds to build. At a height of almost 310 meters, it is the tallest building in Europe. The Shard has completely changed the appearance of London. However, not everyone thinks that it is a change for the better.

    The Shard was designed by the famous Italian architect Renzo Piano. When he began designing the Shard for London, Piano wanted a very tall building that looked like a spire(尖顶). The sides of the building aren't regular. So the building has an unusual shape. And that is how the building got the name：the Shard. Piano says that the spire shape of the Shard is part of a great London tradition. The shape reminds him of the spires of the churches of London or the tall masts(桅杆)of the ships that were once on the river Thames.

    The Shard has 87 floors. At the moment the building is empty, but finally there will be a five-star hotel. There will also be top quality restaurants, apartments and offices.

    Before building work began, a lot of people didn't want the Shard though the plans were approved. Now they are still unhappy about the Shard. Some critics say that such a tall skyscraper might be good in a city like New York, but not in London. They say that the best thing about the Shard is its shape. But that is the only thing. There is no decoration, only flat surfaces. The Egyptians(埃及人)did that 4, 500 years ago.

    Other critics don't like what the Shard seems to represent. They say that the Shard shows how London is becoming more unequal. Only very rich people can afford to buy the expensive apartments and stay in the hotel. But the people living near the Shard are among the poorest in London. So the Shard seems a symbol of the division(分化)in society between the very rich and the poor.

    The Shard now dominates the London skyline. It is not certain, however, that ordinary London citizens will ever accept it as a valuable addition to the city.

    Did you know that Albert Einstein could not speak until he was four years old, and could not read until he was seven? His parents and teachers worried about his mental ability.

    Beethoven's music teacher said about him, "As a composer (作曲家) he is hopeless." What if this young boy had believed it?

    When Thomas Edison was a young boy, his teachers said he was so stupid that he could never learn anything. He once said, "I remember I used to never be able to get along at school. I was always at the foot of my class ... My father thought I was stupid, and I almost decided that I was a stupid person." What if young Thomas had believed what they said about him?

    When the sculptor (雕刻家) Auguste Rodin was young, he had difficulty learning to read and write. Today, we may say he had a learning disability. His father said of him, "I have an idiot (白痴) for a son." His uncle agreed. "He's uneducable," he said. What if Rodin had doubted his ability?

    Walt Disney was once fired by a newspaper editor because he was thought to have no "good ideas". Enrico Caruso was told by one music teacher, "You can't sing. You have no voice at all." And an editor told Louisa May Alcott that she was unable to write anything that would have popular appeal.

    What if these people had listened and become discouraged? Where would our world be without the music of Beethoven, the art of Rodin or the ideas of Albert Einstein and Walt Disney? As Oscar Levant once said, "It's not what you are but what you don't become that hurts."

    You have great potential. When you believe in all you can be, rather than all you cannot become, you will find your place on earth.

    We live in a world where new technologies and new methods are constantly being introduced. As humans, we are learning machines. We are most alive and functioning closest to our potential when we are learning, adapting, adjusting and finding new ways, approaches and techniques to improve our lives or the lives of others in some way.

    Learning does not finish when we leave school. Learning can become a way of life that helps us to achieve our greatest potential. We shall never stop learning, as there is always something new and interesting to discover.

    Lifelong learners never fail, because failure isn't in the vocabulary. Failure is just defined as "a failure to learn".

    When a project does not go according to the plan, lifelong learners ask themselves "What can I learn from this？" and follow up with" How can I do this differently and achieve my outcome？"They do not say, "I did not get to my goal, so I must be a failure."

    There is a wonderful saying: "The only way to fail is to quit！" Robert Kiyosaki, author of Rich Dad, Poor Dad, said, "The only reason I am standing up here and you aren't is that I have failed more often than you have."

    It is sad but true that our greatest lessons come from our greatest failures.The important thing is the lesson. There is no such thing as failure as long as there is a lesson to be learned.

    Learn something new every single day. Three very good reasons for becoming a lifelong learner include promoting your brain's health, giving your life a sense of purpose and promoting your financial security. Any one of these reasons should be enough, but all three combine to a powerful motivation to learn.