If you see a group of people dancing and singing on the street or in the railway station, you don't need to feel surprised. They are a flash mob(快闪族). Who are they Are they mobs? Don't be confused by their name. Actually, a flash mob is a group of people who gather suddenly in a public place, do something unusual for a brief period of time, and then quickly disappear.

    They are usually organized with the help of the Internet or other digital communications networks. The messages may be sent to friends, who send to more people. At a predetermined time, they gather and perform some activities such as exchanging books, coming together to look at the sky, waving their hands and yelling something at the top of their voice for 30 seconds. Then, they quickly disappear before the police can arrive Using mobile phones, the flash mob can change its place if the first one has been cancelled for any reason.

    Bill Wasik, senior editor of Hamper's Magazine, organized the first flash mob in Manhattan in May 2003 and the first successful flash mob gathered on June 3, 2003. Wasik claimed that he created the flash mob as a social experiment designed to laugh at fashion seekers and stress the cultural atmosphere of wanting to be an insider or part of "the next big thing”.

    Flash mob gatherings can sometimes shock people. Such an activity might seem amusing and magical, but it also might frighten people who are not aware of what is taking place. Undoubtedly, flash mob can serve as good political tools and have great potential, such as using flash mob to advertise a product.

    The flash mob is now becoming more and more popular. People use it to do many things. Flash mobs give people from all walks of life an opportunity to come together to create a memory.

    Toronto is reminding citizens this month what exactly can and can't go into the blue bins an you may be surprised at what can't be recycled. As it turns out the takeout coffee cups you've been throwing into the recycling actually have to go in the garbage.

    The city's “recycle right” web explains that food left after a meal, woven (编织的) cloth, old VHS tapes and other things have been turning up in blue bins, where they don't belong.

    According to the city, about 45,000 tunes of garbage was mistakenly put into recycling bins last year alone.

    Among those things are the takeout coffee and tea cups we get while were on the go. The city says that because those paper cups are lined with plastic or wax they can't be recycled. The black plastic coffee lids (盖子) also can't go in the blue bin, although non-black plastic lids can be recycled.

    Emily Alfred, senior campaigner with the Toronto Environmental Alliance, said, “Millions of cups are used in Toronto every year and people are taking these out and putting them in the wrong bin.”

    When paper coffee cups are thrown in with the recycling. Alfred said, they produce a harmful effect on the system.

    “They can't separate the plastic and paper in a typical paper recycling center,” Alfred said, “so it just causes pollution of the recycling process, and it causes lower-quality paper if it does get recycled.”

    “New regulations passed last month call for changes to be rolled out over the next few years regarding what products companies can sell,” Alfred said. Her organization will be pushing for more producer responsibility laws, which call on companies that design and make products to take on the responsibility of recycling them.

    For now, consumers can consider carrying their own reusable coffee cups while they are on the go, ask for a ceramic mug (陶瓷杯) if they plan to consume their drink in the cafe, and support their local government officials if they have put efforts into changing recycling or producer responsibility laws.

    Alfred said, “I think people can change their habits easily if they understand what to do.”

    "An apple a day keeps the doctor away" is one of the most common sayings in the English languages. This is because apples were one of the first foods that medical professionals recognized as healthy­their benefits became obvious when  quite simply, doctors found that people who ate apples were sick less often than those who did not. Today we have a more specific understanding of why apples are so beneficial to overall health.

    Apples can help keep your levels of bad cholesterol (胆固醇) down. The pectin (果胶) in apples helps you to maintain cardiovascular health and reduce LDL cholesterol(which is the "bad" kind). Apples themselves do not add cholesterol to your diet and are full of water and fiber to help prevent the cholesterol in other foods you might digest. According to Health Diaries, people who eat two apples per day may lower their cholesterol by as much as 16 percent.

    Apples are naturally low in calories and high in water content. Eating an apple can satisfy your hunger and keep you from reaching for high-sugar, high-calories snacks. By eating apples, you will be more able to maintain a healthy weight because they fill you up, potentially stopping you from eating food that encourages a waistline increase.

    Apples contain respectable levels of boron (硼) which helps build healthy bones, and can also prevent diseases like arthritis. Apples are rich in vitamin C, which is known to help build immunity.

    Studies have shown that apples can decrease the risk of breast cancer, colon cancer, and liver cancer. One theory is that the apple skins are responsible for this, so be sure not to peel your apple before you eat them, as you could remove some of the health benefits.

    Moving smoothly and silently through Alibaba Group Holding Ltd's futuristic "FlyZoo" hotel, black disc-shaped robots about a metre in height deliver food and drop off fresh towels.

    The robots are part of a set of high-tech tools that Alibaba says strongly cuts the hotel's cost of human labour and eliminates the need for guests to interact with other people.

    Formally opened to the public last month, the 290-room FlyZoo is an incubator for technology Alibaba wants to sell to the hotel industry in the future and an opportunity to showcase its prowess in artificial intelligence. It is also an experiment that tests consumer comfort levels with unmanned commerce in China.

    Inside the hotel, softly-lit white panelled walls bring to mind the interiors of Hollywood spaceships. Guests check in at podiums that scan their faces, as well as passports or other ID. Visitors with a Chinese national ID can scan their faces using their smartphones to check in ahead of time.

    Elevators scan guests' faces again to verify which floor they can access and hotel room doors are opened with another face scan.

    "It's very quick and safe. I haven't used it much yet, but basically, I can be in my room in one minute, "said guest Tracy Li. Li added that safety was one of her priorities and she was pleased her room could only be entered with a scan of her face.

    In the rooms, Alibaba's voice command technology is used to change the temperature, close the curtains, adjust the lighting and order room service.

    At the hotel's restaurant, taller capsule-shaped robots deliver food that guests have ordered via the FlyZoo app while at a separate bar, a large robotic arm can mix more than 20 different types of cocktails. Facial recognition cameras add charges to the room rate automatically.

    The hotel does employ humans, though Alibaba declined to detail how many. This includes chefs and cleaners as well as reception staff, who will assist with conventional check-in procedures for guests unwilling to have their faces scanned and want to use electronic key cards.

    When you visit America, you will see the word Motel on signs and notice boards. It is made up of "motor" and "hotel" and it is really a hotel for people who arrive by car (however, you don't need a car to stay at one). You have to pay when you arrive for your room, which usually has a bath. Meals are not provided, but there will certainly be a cafeteria (自助餐馆). Americans eat a lot of salads and sandwiches. Along the main roads there are a lot of motels. Each tries to offer more than next. Some provide television in every bedroom; others have swimming pools; and so on. Motels are especially useful when you are in the country, far from a town or city. You will also find them in the big National Parks.

    In these great National Parks, you may meet guests you don't expect to see. An American friend told me a little story. In the middle of a moonless night she heard strange noises outside her motel window in the Yellowstone National Park in Wyoming. Thinking it might be a thief, she jumped out of bed, opened the door and crept towards a dark shadow. As she got close, she saw the thief. She was dreadfully frightened: it wasn't a human thief ­ it was a big black bear. The bear was turning over some empty tins with its paw, looking for tasty bits of food. My friend decided to leave that particular thief alone!

    There are also, of course, places called "rooming houses", where they receive lodgers (房客). You will see such signs as Tourists or Rooms Rent, and you could try one of these. A word of warning ­ looking for a room in New York during the tourist season is like looking for gold on the moon!

    Every morning, Ben Mumford starts his school day with math. At the age of ten, he is already working at GCSE level, but he does not always bother to get out of his pajamas (睡衣裤) in time for the class. He reads more books than most of his friends, studies science on the beach, and recently built a go-kart (卡丁车) in a technology lesson. Ben is happy and fulfilled, all, his mother believes, thanks to homeschooling.

    Homeschooling is not what it used to be. What emerged in the 1970s as a way for Catholic (信天主教的) parents to infuse (灌输) religion into their kids' education is now probably the fastest-growing form of education in the U.K. The number of homeschooled children has risen by about 40 percent over three years. Here are a handful of reasons why homeschooling makes sense in the 21^st century.

    Contrary to the name, homeschooling takes place in an actual home only a small part of time. A great deal of instruction happens in libraries, museums and community colleges. These experiences have the effect of helping kids mature much more quickly and developing a trait of open-mindedness.

    The key idea of homeschooling is that kids need to learn at the speed, and in the style, most appropriate for them. Without formal curriculum to guide their education, homeschoolers get the chance to explore a range of topics that might not be normally offered until high school or college. They can study psychology in the fourth grade, or finance in the eighth grade.

    The most common misunderstanding about homeschoolers is that they lack social skills. However, social media makes it convenient for homeschoolers of today to have just as much opportunity to make friends as kids studying in traditional schools. Meanwhile, they do not need to deal with the potential problems of being around kids in a school environment, including bullying, which might result in anxiety and depression.

    For most people, school is really good, and it works for them because they learn in the way that school teaches. However, there are so many different ways of learning and processing (处理) information and knowledge. It does not necessarily work for everyone.