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.

    While Jennifer was at home taking an online exam for her business law class, a monitor（监控器）a few hundred miles away was watching her every move.

    Using a web camera equipped in Jennifer's Los Angeles apartment, the monitor in Phoenix tracked how frequently her eyes moved from the computer screen and listened for the secret sounds of a possible helper in the room. Her Internet access was locked — remotely — to prevent Internet searches, and her typing style was analyzed to make sure she was who she said she was: Did she enter her student number at the same speed as she had in the past? Or was she slowing down?

    In the battle against cheating, this is the cutting edge and a key to encouraging honesty in the booming field of online education. The technology gives trust to the entire system, to the institution and to online education in general. Only with solid measures against cheating, experts say, can Internet universities show that their exams and diplomas are valid — that students haven't just searched the Internet to get the right answers.

    Although online classes have existed for more than a decade, the concern over cheating has become sharper in the last year with the growth of “open online courses”. Private colleges, public universities and corporations are jumping into the online education field, spending millions of dollars to attract potential students, while also taking steps to help guarantee honesty at a distance.

    Aside from the web cameras, a number of other high-tech methods are becoming increasingly popular. Among them are programs that check students' identities using personal information, such as the telephone number they once used.

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    There's a whole lot of things that people fill their stomachs with. Some of them keep people alive. Some of them taste good to people. Some of them help people win pie-eating contests. Alcohol does none of these things. Why do people keep drinking it? And what does it do once it gets to their stomachs?

    There are all kinds of alcohol molecules (分子), but the one that people most often pour down their throat is ethanol (乙醇). Ethanol is very tiny and it dissolves in water, so it gets into all sorts of places that it's not supposed to. Alcohol heads for the digestive system. Because it dissolves in water, it can get into the water in the bloodstream. Because ethanol, to a certain extent, can pass through cell membranes(膜). It can go almost anywhere. It spreads through the muscles, and is sweated（出汗） — unmetabolized(未经新陈代谢的) and whole — through the skin. It gets into the heart. It even takes a walk through the brain, and this is the secret of its powers.

    Alcohol depresses the nerves, and the nerves affect almost every area of the body. Enough alcohol makes people sleep, so people who become unconscious choke on their own vomit (呕吐物). Most worryingly, enough alcohol can shut down those parts of the brain just like any other parts. People become unconscious and their brains simply forget to breathe.

    Alcohol is broken down in the liver. Alcohol doesn't destroy the liver, but products that the liver breaks the alcohol into do cause damage. A glass of wine per day can not do any harm. Instead, it can prevent heart attacks or can make someone functionally young. And it is kind of nice to know that sometimes, relaxation and cheer can be bottled. All that's needed is to take care how much alcohol is let into a person's brain.

    When I was a child, my grandmother Adele took me to museums, restaurants, dances. She showered me gifts from her travels around the world. But I can only remember a book she gave me—one book that, to this day, I have not read. She presented me with her own favorite childhood book: Hans Brinker. My grandmother was happy to share this book with me. She even decorated the title page with her proud writing.

    I tried to read it. I adored reading, and would dive into a new pile of books from the library all at once. But something about Hans Brinker just wouldn't let me in. The story was set in Holland, a long time ago. It felt dull and unfamiliar, even though I was a fan of classics of other times and places. I simply read the first pages over and over. I could not progress.

    Standing on a bookshelf in our living room, the book was like something I avoided. It scolded me for not being interested, for not trying hard enough, for disappointing my grandmother. The book started to fit in, almost forgotten, until Adele asked. Had I read it? Did I like it? Always determined, she wanted to know the answer. I would make some kind of excuse, but feel bad, and open it again, hoping for a new reaction. The book weighed on me.

    Years passed and finally Adele and I both accepted that I would never read Hans Brinker. Eventually I cleared the book from the shelf. The Hans Brinker experience led me to set a rule that I've lived by ever since: Do not ask about a book given as a gift and don't let anything become your barrier. What Adele originally wanted to do is to give book-giving special meaning, but she increased the possibility of the owner to be a disappointment.

    They are called "sea parrots", and sometimes "clowns (小丑) of the sea"!

    Atlantic puffins (海鹦) are small seabirds which are around 25 cm in length. They have black and white feathers and a large parrot-like beak (鸟喙). The beak changes color during the year. In winter, the beak has a dull gray color, but it turns orange in spring!

    Puffins spend most of their lives out at sea, resting on the waves when not swimming. They live on the eastern coast of Canada and the United States, and the western coast of Europe.

    Puffins live off small fish such as herring, hake and sand eels. Puffins flap (拍) their wings up to 400 times a minute and speeding through the air at up to 88 km an hour. Wow! What's more, puffins can dive down 60m under water in search of their favorite fish.

    In spring and summer, thousands of puffins stay together on the coasts and islands of the North Atlantic Ocean to start a puffin family. They usually pair up with the same partner as before some may have been together for 20 years! Puffins dig out a hole usually in a grassy bank. Both parents take it in turn to incubate (孵化) the egg for the next 36-45 days!

Although puffins are not classed as an endangered animal, their population in some places is becoming smaller. The main reasons are overfishing, which can lead to a shortage of food for puffins, and pollution—especially oil spills (溢出). Not only does the oil make these beautiful birds sick, it harms their feathers.

China is the home of tea. Since ancient times, tea {#blank#}1{#/blank#} (become) part of Chinese culture, leaving its smell in poems and customs. Many tea lovers enjoy tea not only for its taste, {#blank#}2{#/blank#} for the beauty of tea ceremonies.

 {#blank#}3{#/blank#} (traditional), picking tea leaves is an important activity in spring in South China. The earliest batch (批) of tea is often ready to be picked before Qingming, in early April {#blank#}4{#/blank#} the temperature begins to rise and rain increases. This kind of tea, called Mingqian tea, is {#blank#}5{#/blank#} (high) praised for its good quality.

East China's Zhejiang province is considered as {#blank#}6{#/blank#} major producer of tea. White Tea in Huzhou city's Anji county and West Lake Longjing Tea in Hangzhou are famous in both China and abroad. In spring, local hills of those places are filled with tea workers {#blank#}7{#/blank#}(work) on their land. In the busy seasons, {#blank#}8{#/blank#} (tourist) from different areas of the country travel there {#blank#}9{#/blank#} (see) the sights of tea farms and enjoy a freshly prepared cup of tea.

Thousands of years ago, by the hands of the Chinese people, a leaf {#blank#}10{#/blank#} (make) into a delicious drink. It has traveled a long way and continues to play a role in Chinese culture.