At no time in history has there been such a mass movement of people from the countryside to the city as is happening now. By the year 2030, it's estimated that more than two thirds of the world's population will be living in cities, twice as many as today. This means that the problems faced by cities today-overcrowding, poor housing, unemployment, poverty and lack of food and water—will be twice as bad, unless we find solutions soon.

    Another serious issue is how to provide good transportation for their citizens. Many of the world's major cities are already struggling with out-of-date transport infrastructures (基本设施). How can they deal with the additional demands?

    London is a good example. Its enlargement was made possible by the invention of the steam engine, which powered the world's first underground railway. But its transport system are now hopelessly out-of-date and need urgent modernization. London's future success depends very much on developing better public transport

    Over a million people travel into central London every day from outside the city. They, together with the people who live in London, want a public transport system that is efficient, safe and environmentally friendly. What they often get, however, falls far short of that ideal. Passengers complain about cost and pollution, while businesses worry about the problems their staff have in getting to work on time. Yes, the proportion of London households that own a car grew from just over ten percent in the early 1950s to over sixty percent today.

    As the city has become increasingly crowded and polluted, there has been a growing realization that action must be taken soon.

    You probably know you should say” please” and “thank you ” at restaurants. You probably know the rules of a library. You know you should respect and be nice to your classmates. But do you have music manners?

    Keep It Down! You have to notice the volume of your music. You should not play your music so loud that everyone around you can hear it. Some people might even get angry. Usually, when you play the music loud on an MP3 player, other people can't hear the words of the song. They just hear a loud sound. Not one wants to listen to this. Very loud music can also be bad for your ears, so even if you are alone when listening to our MP3 player, you shouldn't have it turned up too high.

    Take Them Off! You need to know when to turn your MP3 player off and put it away. Libraries and schools don't allow MP3 players. There are other places, like museums, that don't have rules, but it would be rude to have your MP3 player on. Sometimes, it just doesn't make sense（没意义） to listen your MP3 player at event. Why would you listen to music at a play, a movie or a sporting event? You would miss what is going on and others would wonder why you even came.

    Take One Out! Once in a while it's okay just to take out one earphone and not the other. Imagine you are listening to your MP3 player when someone asks you the way. It would not be rude to take out one earphone, tell him the way, and put back the earphone and continue listening. You can also do this when you order food at a fast-food restaurant.

    It's Your Choice! There are times when you need to decide what is best. For example, some people can listen to music on their MP3 Players when read books, while others think it is disturbing. In cases like this, you need to do what seems right for you.

    Being physically active three times a week reduces the odds of being depressed by about 16%, according to new UCL research carried out as part of the Public Health Research Centre.

    The study, published in JAMA Psychiatry, found a two-way relationship between depression and physical activity. People who increased their weekly activity were reported to have fewer depressive symptoms but those with more depressive symptoms were less active, particularly at younger ages.

    Researchers followed 11,135 people born in 1958 up until the age of 50, recording depressive symptoms and levels of physical activity at regular intervals in adulthood. They found that each additional activity period per week reduced odds of depression by 6%. In England 19% of men and 26% of women are currently classed as "inactive", and this study suggests that activity could significantly improve their mental as well as physical health.

    "Assuming the association is causal, physical activity has a protective effect against depression. If an adult between his twenties and forties who isn't physically active became active 3 times per week, he would reduce his risks of depression by about 16%," said Dr Snehal of the UCL Institute of Child Health, lead author of the study.

    Professor Mark，Director of the Public Health Research Centre, said: "Many people are already aware of the benefits of physical activity on their general health, but now we are seeing more evidence that suggests it also has a positive effect on a person's mental well-being. The latest research highlights just how important it is to ensure that people are working and living in environments that allow them to be both physically active and mentally healthy."

    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.

    Audrey Hepburn(奥黛丽·赫本) won an Academy Award as Best Actress for her first major American movie, Roman Holiday, which was released in 1953. But she is remembered as much for her aid work as for her acting.

    Born in Belgium in 1929, Audrey's father was British and her mother was Dutch. Audrey was sent to live at a British school for part of her childhood. During World War II, she lived and studied in the Netherlands. Her mother thought it would be safe from German attacks. Audrey studied dance as a teenager and during college. But when she returned to London after the war she realized she wasn't going to be a ballerina (芭蕾舞女演员). So she began taking acting parts in stage shows. Late she began to get small parts in movies.

    But it was Audrey Hepburn's move to America in 1950s that brought her true fame. In 1951 she played the character “Gigi” in the Broadway play of the same name and received great critical praise. Two years later, Roman Holiday made her a star at the age of 24.

    Audrey Hepburn made more than 25 movies. Among her roles, the most popular one was Holly Golightly in Breakfast at Tiffany's in 1961. Three years later she played Eliza Doolittle in My Fair Lady.

    She was married two times and had one child with each husband. In 1989, the UN Children's Fund named Audrey a goodwill amassador. She travelled all over the world in support of UNICEF（联合国儿童基金会）projects. The UN agency said she was a tireless worker. She often gave 15 interviews a day to gain money and support for UNICEF projects.

    Audrey Hepburn often said her loyalty to UNICEF was the result of her experiences as a child during World War II. She said she knew what it was like to be starving and to be saved by international aid. She was a goodwill amassador until her death in 1993 from colon cancer.

Starting a club of some kind at school can be difficult. But with a good idea, some active friends, and the right knowledge, you can pull it off. {#blank#}1{#/blank#}.

Decide whether you really want to start a club. Once you have strong enough support from your friends and fellow students, you're ready to go.

{#blank#}2{#/blank#}. Find an advisor for your club. Pick someone who will help you organize events for your club.

Find a place. {#blank#}3{#/blank#} If you want to do this,  talk to your headteacher to apply (申请) for a classroom.

Decide when to meet. Decide how often your club should meet, and then pick a convenient time and day when most club members will be free.

Advertise your club at school. Make bright, colorful informative posters (海报) that will attract attention. {#blank#}4{#/blank#}.

Plan volunteering events. You can decide on events yourself, or hold a meeting to get your club's opinion. {#blank#}5{#/blank#}

Have fun. What's the point of having a club if it's no fun? Don't take yourself too seriously and be sure to have a sense of humor.