In many high schools，there are strict rules about using mobile phones. If your phone rings in class，for example，the teacher will be very angry.
   Every mobile phone has a ringtone (铃声). It tells you that someone is calling you. Now，there is a ringtone called “mosquitotone (蚊子铃声)”. Using it，students can receive calls and text messages (短信) in class but the teacher will not realize what is happening. How?
   Mosquitotone has a special sound. Only children and teenagers can hear it. As we get older，we are unable to hear some sounds with high frequencies (频率). As a result，a child or teenager can hear the mosquitotone ringtone, but it's_inaudible_to someone 20 or older.
   But sometimes，people over 20 can hear the ringtone. One British student's phone uses mosquitotone. In class，the student's phone rang. The 32­year­old teacher looked at the student and became unhappy. “I heard that. You know the rule：no mobile phone in class.”
   Not all the students are interested in mosquitotone. Jerry Jones，a high school student of 17，says，“Using mosquitotone too often is bad for our hearing. I may use it for pleasure，but not in class. It's unfair to the teachers！”
   What do parents think of mosquitotone？“I think it is perfect for places like movie theaters，” says Connie Neeson,44.“Think about it. Yon're watching a film and someone's mobile phone rings. Mosquitotone is good because many people don't hear it. However，it also has a bad influence on their study if students use it in class.”

    For most of people in the west，Valentine's Day(情人节) ends on February 15，but here in Japan it's not quite over until March 15.March 14—exactly one month after Valentine's Day—is White Day in Japan.

    To really understand what White Day is all about，you have to understand what Valentine's Day in Japan is like. Japanese Valentine's Day is all about men getting presents. Japanese women are usually too shy to show their love，though it might not be true today. Valentine's Day is a great chance to let women show their feelings. Men should return gifts to women on White Day.

    On both days，chocolate is the gift of choice. More often，the colour of the chocolate is white because of the name of the day. You can also buy flowers，candy，or cookies.

    Does it sound good to you? Don't get too excited when you get chocolate from Japanese girls! They give chocolate not only to their loved ones，but also to men such as bosses (老板) and male(男性的) friends.

    The Japanese first celebrated White Day in 1978.Now it is also celebrated in South Korea and Taiwan，China.

    Studying different languages increases our understanding of how humans communicate and their different cultures. However, almost 80% of the people in the world speak only 1% of its languages.  Every 14 days a language dies. By 2100, half of the more than 7, 000 languages spoken on Earth today may disappear.

    Throughout history, the languages of dominant(统治的)groups have spread while the languages of native cultures have become extinct. This happens because of government language policies, or because the dominant language becomes more useful in everyday life. Furthermore, many endangered languages aren't written down. When the last speakers of a language die and their language becomes extinct, their stories, songs, and other important information are lost, too.

    Central South America has some of the world's most endangered languages. The Kallawaya people speak a secret language that has details of thousands of medical plants. Today, fewer than 100 people speak it. In Central and Eastern Siberia, many Siberian languages now have only a few elderly speakers. Yuchi, which may be unrelated to any other language in the world, is one of the many native languages used in Oklahoma, the U.S.A. It is disappearing rapidly. In 2010, only five elderly people could speak this language.

    Luckily, native cultures around the world are using modern technology to help keep their endangered languages and cultures alive. Communities are creating dictionaries and libraries by using pictures, video, and audio to record the traditions of the last speakers of their language. If the young people don't speak and understand the words and stories of their ancestors(祖先), the language will die.

    And when the language dies, part of the culture dies, too.

    Few words are spoken more often every day on the streets of Britain than "I'm sorry". This phrase has become such a common response(反应) that it has taken on a lot of meanings.

    Saying "Sorry" means to apologize(道歉). This is simple and easy to understand. We learn it both as a native speaker and as a student of foreign languages.

    But in Britain, it takes on another meaning. It is a cultural expression. Imagine this: a man walks down the street, looking down at his phone. A woman is walking in the opposite direction, towards the man. She sees him, but she can't get out of the way in time. The man bumps (碰撞) into the woman. Who should say sorry? Naturally, the man should say sorry, because it was he who wasn't looking where he was going. Yet in Britain, it is common for both to apologize.

    It is known that British people, like most people, do not enjoy conflict(冲突).So to quickly calm the situation, British people will apologize to each other.

    Other times it may sound funny to hear "sorry". Some of my friends say it at restaurants, as they ask the waiter: "Sorry, but can I order another drink?" It is not to apologize, but just to express that we need the waiter. In Britain, sorry doesn't always mean exactly what you think.

    All around the world, people drink tea. But tea does not mean the same thing to everyone. In different countries people have very different ideas about drinking tea.

    In China, for example, tea is always served when people get together. The Chinese drink it at any time of the day at homes or in teahouses. They prefer(更喜欢) their tea plain, with nothing else in it.

    Tea is also important in Japan. The Japanese have a special way of serving(招待) tea called a tea ceremony(仪式) .It is very old and full of meaning. Everything must be done in a special way in the ceremony. There is even a special room for it in Japanese homes.

    Another tea-drinking country is England. In England, the late afternoon is "teatime".

    Almost everyone has a cup of tea then. The English usually make tea in a teapot and drink it with cream and sugar. They also eat cakes, cookies and little sandwiches at teatime.

    In the United States people drink tea mostly for breakfast or after meals. Americans usually use tea bags to make their tea. Tea bags are faster and easier than making tea in teapots. In summer, many Americans drink "iced tea". Sometimes they drink iced tea from cans, like soda.