Suppose you are a visitor in the land of Mongolia, some friends ask you to eat with them. What kind of manners do they want you to have? They want you to give a loud burp after you finish eating. Burping would show that you like your food. In some countries, if you give a big burp, you are told to say “Excuse me, please”.

    In many places people like to eat together. But in some parts of Polynesia it is bad manners to be seen eating at all. People show their good manners by turning their backs on others while they eat.

    What are manners like in an East African town? The people try not to see you. They are being polite. You may see a friend. He may not see you at all. If you are polite, you will sit down beside him. You will wait until he finishes what he is doing. Then he will talk to you. Manners are different all over the world. But it is good to know that all manners begin in the same way. People need ways to show that they want to be friends.

    Angad Rekhi, a graduate student and an assistant professor of electrical engineering, has developed a wake-up receiver. This wake-up receiver has many potential applications, particularly in designing the next generation of net worked devices, including so called "smart" devices that can communicate directly with one another without human intervention (介入).

    Once attached to a device, a wake-up receiver listens for a unique ultrasonic（超声波）pattern that tells it when to turn the device on. It needs only a very small amount of power to maintain this constant listening, so it still saves energy overall while extending the battery life of the larger device. A well-designed wake-up receiver also allows the device to be turned on from a significant distance.

    Given the increased interest in networked devices, researchers and industry organizations are starting to define what features and techniques will become standard. Regardless of whether this ultrasound wake-up receiver is among these standard designs, it is likely wake-up receivers of some kind will be combined into commercial applications soon.

    By comparison, the ultrasound wake-up receiver requires a battery but has much greater range than the wirelessly powered devices, while still maintaining a long lifetime due to extremely low power draw. These two technologies-wireless power and wake-up receivers-would likely serve different purposes but both indicate at a turning point in devices that make up the Internet of Things.

    "In light of a long-promised future where interconnected, autonomous, widespread and unremarkable technologies make life easier, the networked devices available now, like video doorbells and app-enabled lights, seem like rather slight advances." the researchers said. They believe technologies like theirs could help cross the gap between the Internet of Things as we know it and the Internet of Things at its best-whatever that may be.

    4-Day Classic Beijing Tour The 4-day classic Beijing tour is designed for tourists who come to visit China for the first time. It covers the most popular and typical places in Beijing, fully displaying the scenery, culture, history, local lifestyles and features, food and drinks, business, etc. for you.

    Day 1：Arrival in Beijing

    Your guide meets you at Capital Airport, and helps you check in at your hotel.

    Enjoy Beijing Duck as welcome dinner.

    Accommodation：Beijing downtown

    Day 2：The Great Wall & the Summer Palace

    Start your day at the most famous part of the Great Wall, the Badaling Great Wall. Leave the downtown for the Great Wall at 8am. Since it is a long drive to the Great Wall （about 2 hours' riding） have a break at the Jade Museum on the way. Lunch will be enjoyed in a local restaurant. In the early afternoon come back to the city and have a sightseeing tour of the Summer Palace.

    Recommended Activity：Beijing Opera Show （Liyuan Theatre, 19：30-21：10 every evening）

    Accommodation：Beijing downtown

    Day 3：Beijing city sightseeing & Local experience

    Your guide meets you at the hotel at 8 am and set out for the day's touring：    Tian'anmen Square and the Forbidden City.

    After visiting the two sites, have a break and get ready for lunch.

    Hutong visit：see some traditional arts of the old Beijing, such as paper cutting and kite making, and visit a local family.

    Accommodation：Beijing downtown

    Day 4：Beijing Olympic sites

    Visit the Olympic sites：Bird's Nest, Water Cube and Olympic Park, witnessing the fast developing modern China. Enjoy some free time after visiting the sites.

    After lunch, it is shopping time and then the tour is over.

    The first day my new teacher walked into our school in Spanish Harlem, I burst out laughing. Ron Clark was this young white guy from North Carolina who talked with a funny Southern accent(口音). He said he used to be a singing waiter. I thought, who is this guy? He's a complete joke.

    It was 1999 and I was in the fifth grade at New York City's P.S. 83. I guessed I'd spend most of the year in the headmaster's office. I'd always been a troublemaker. I'd get shouted at, and then the teachers would give up on me. I thought that's what would happen with Ron Clark.

    I was wrong. That first week, I kept laughing at him. He pulled me out to the hallway and said I'd better shape up(表现好). "Tamara," he said, "you're a smart kid. You can do better."

    He told me I was a natural leader and that I'd go far in life if I started studying hard. I was mad at first, but then something happened: I began to respect him. There were 29 students in our class, and it didn't take long for us to realize that Ron Clark was no ordinary teacher.

    Like most teachers, he had lots of rules: Treat each other like family. Don't cut in line. But the real difference was how concerned he was. Mr. Clark ate with us in the lunchroom instead of going to the teachers' day-room. At first, my friends and I were thinking. What is he doing?

    He asked us what was going on in our lives. Between classes, he came outside with us, and we taught him how to jump rope. When it snowed, Mr. Clark, who'd never seen snow before, threw us with snowballs, and we threw him back.

    Before coming to P.S. 83, he taught at Snowden Elementary in his hometown, Belhaven, North Carolina. His parents were DJs(流行音乐节目主持人)at dance clubs, so he grew up with music and energy. He wanted a life of adventure, he told me, but his mom encouraged him to ask for a position at Snowden when one of the teachers passed away. Mr. Clark ended up loving it. He came to Harlem because he'd seen a TV show about our troubled schools and the lack of qualified teachers. He wanted a challenge. Boy, did he get one.

    When the telephone rings late at night, most women guess it must be one of only four or five people calling. A sister? Maybe. An emergency? Possibly. A mother? Probably not at that time of night. Much more probably it is a close female friend calling to tell you that she is heartbroken because she has split up with her boyfriend again or perhaps simply that a good movie has just started on TV.

    At a time when families are spread far and wide and marriages often end in divorce, friendships are becoming more and more important. Erika, a 32-year-old lawyer, is strengthened by her ten year friendship with her married friend Jane. "I was very sick one night, so I called Jane at about 3：00 a. m. to talk about it," she says. "She was very supportive and even came over to take me to the doctor's."

    As American TV shows like Friends have become more popular, many of us are beginning to see the value of such friendships.TV shows like this tell us that our romantic relationships may not last, but we need to keep in touch with our close friends if we want to survive.

    With Erika's family 200 miles away, it is Jane who keeps a spare set of keys to Erika's apartment and waters her plants whenever she is away. "Having Jane around gives me a certain amount of freedom. It is not the kind of thing that you could ask anyone to do, but she knows I would do the same for her. "Jane, who may move to a different city soon, is worried about leaving such a support system of friends. "My friends have more to do with my life than my parents and, therefore, I don't have to spend a lot of time explaining things to them. Friends are more up to date with what is happening."

    Most people agree that eating healthy food is important. But sometimes making good food choices can be difficult. Now, there are apps that can help people learn about the food they eat to improve their health and their dining out experience.

    Open Table app

    Open Table app helps people choose restaurants when they want to go out to eat. It is a free service that shows users restaurant available based on where and when they want to dine. It gives users points when they make reservations(预定), which can add up to discounts on restaurant visits.

    Max McCalman's Cheese&Wine Pairing app

    Wine and cheese can be a great combination. But which wines go best with which cheeses? Max McCalman's Cheese&Wine Pairing app can help. It provides information about hundreds of different cheeses and suggests wines to pair with each. Max McCalman's Cheese&Wine Pairing app is free.

    HappyCow app

Vegetarians do not eat animal meat. Vegans do not eat any animal products. The HappyCow app is made for both groups. Users can search for vegetarian-vegan restaurants and stores around the world.

    LocalEats app

    Restaurant chains, like McDonalds, can be found almost anywhere a person might travel. But sometimes travelers want to eat like locals. The LocalEats app is designed for that. It can help you find local restaurants in major cities in the US and in other countries. It costs about a dollar.

    Where Chefs Eat app

    "Where Chefs Eat" is a 975-pagc book. Most people would not want to carry that around. But there is a much lighter app version of the same name for just $15. Six hundred chefs provide information on 3,000 restaurants around the world on the Where Chefs Eat app.