Disposing (处理) of waste has been a problem since humans started producing it. As more and more people choose to live close together in cities，the waste disposal problem becomes increasingly difficult.

    During the eighteenth century，it was usual for several neighboring towns to get together to select a faraway spot as a dump site. People would transport household rubbish，rotted wood and old possessions to the site. Regularly some of the trash was burned and the rest was buried. The unpleasant sights and smells caused no problem because nobody lived close by. Factories and some other industrial sites also had waste to be disposed of. Those located on rivers often just poured the unwanted remains into the water. Others built huge burners with chimneys to deal with the problem.

    Several facts make these choices unacceptable to modern society. The first problem is space. Dumps(垃圾场)， are most needed in heavily populated areas. Such areas rarely have empty land suitable. Farm areas are refusing to accept rubbish from elsewhere，cheap land in major city areas to dispose wastes is nonexistent(不存在的). Awareness of pollution dangers has resulted in more strict rules of waste disposal. Pollution of rivers，ground water，land and air is a price people can no longer pay to get rid of waste. The amount of waste，however， continues to grow.

    Recycling efforts have become commonplace，and many towns require their people to take part. Even the most efficient recycling programs，however，can hope to deal with only about 50 percent of a city's reusable waste，so more people should be involved in recycling programs.

The National Gallery

Description:

    The National Gallery is the British national art museum built on the north side of Trafalgar Square in London. It houses a different collection of more than 2,300 examples of European art ranging from 13th-century religious paintings to more modem ones by Renoir and Van Gogh. The older collections of the gallery are reached through the main entrance while the more modem works in the East Wing are most easily reached from Trafalgar Square by a ground floor entrance

    Layout:

    The modem Sainsbury Wing on the western side of the building houses 13th- to 15th-century paintings, and artists include Duccio, Uccello, Van Eyck, Lippi, Mantegna, Botticelli and Memling.

    The main West Wing houses 16th-century paintings, and artists include Leonardo da Vinci, Cranach, Michelangelo, Raphael, Bruegel, Bronzino, Titan and Veronese.

    The North Wing houses 17th-century paintings, and artists include Caravaggio, Rubens, Poussin, Van Dyck, Velazquez, Claude and Vermeer.

    The East Wing houses 18th- to early 20th-century paintings, and artists include Canaletto, Goya, Turner, Constable, Renoir and Van Gogh.

Opening Hours:

    The Gallery is open every day from 10am to 6pm (Fridays 10am to 9pm) and is free, but charges apply to some special exhibitions.

Getting There:

    Nearest underground stations: Charing Cross (2-minute walk), Leicester Square (3-minute walk), Embankment (7-minute walk), and Piccadilly Circus (8-minute walk).

    For many, music is as important to the human experience as eating and breathing. We hear music everywhere—at home, the gym, parties and stores. But what kind of music do we prefer to listen to, and when and why do our musical preferences change?

    The relationship between the change of seasons and musical preferences was the focus of a study led by psychologist Terry Pettijohn. He and his team based their research on a previous study that examined the relationship between popular music preferences and the Environmental Security Hypothesis(假设). The results showed that over time, when social and financial conditions were more risky, the songs of the year that were slower, longer, more comforting and serious were most popular. And during periods in which social and financial conditions were generally stable, the result was opposite.

    Building on these findings, Pettijohn and his team wondered if the Hypothesis could also be applied to the change of seasons. For college students, the participants in this study, autumn begins at the start of the school year. Gone are the carefree days of summer, when school is out. Winter means colder temperatures, shorter days, and, in many places in the country, snow. Spring, however, is a different story. It represents a fresh start and when clocks spring forward, we gain an extra hour of daylight. As students walk into summer, they're absorbed in the sunshine and social activities—and enjoy a break from school.

    But do changing seasonal conditions influence musical preferences? To answer this question, the researchers designed two studies. What did they find? Both groups of college students favored more serious music during the seasons of fall and winter, and more active and energetic music during the spring and summer seasons. And these findings, Pettijohn argues, have practical significances.

    Teenagers who spend hours in front of the television may have a poorer diet as young adults.

    A study, which included nearly 1,400 high school students, found those who watched TV for five hours or more per day had less healthy diets than peers(同龄人）five years later. Why does this happen? Should the parents take any measures?

    On the one hand, people who spend a lot of time in front of the TV, especially teenagers, may snack more, and that may affect their long-term diet quality.

    On the other hand, TV ads for fast food, sweets and snacks tempt teenagers to eat more of those foods. And TV time might also replace exercise time for some kids.

Lead researcher Dr. Daheia J. Barr-Anderson, of the University of Minnesota in Minneapolis, told Reuters Health a clear correlation between TV time during high school and diet quality in young adulthood. While the heaviest TV viewers were eating the most junk food , those who'd watched less than two hours per day had the highest intake(吸收)of fruits, vegetables, whole grains and high-calcium food. In her opinion, parents should limit and monitor TV viewing.

    As far as I am concerned, children should watch no more than two hours of television per day. And parents should set a good example by eating right, being physically active and curbing their own TV time.

    Lily went to London with her parents for a two-week vacation. She sent postcards to her friends.

Libraries

    Public libraries

    Most towns in Britain have a public library. A library usually has a large selection of books and other resources, which library members can use and borrow for free.

    Britain's First Public Library

    The first public library in Britain opened in Manchester in1852. It's first librarian was a man called Edward Edwards, Edwards attended the library's opening ceremony and two famous writers called Charles Dickens and William Thackeray were there too.

    How to Join a Library

    To join a library, go to your local library and fill in a form. You'll receive a library card which is needed when using library services.

    Mobile Libraries

    Not everyone can get a library. Some people live far away from towns and cities. Other people find it difficult to go out because they have an illness or a disability. Thanks to mobile libraries, these people can still borrow books.

    Unlike most libraries, which store books in buildings, mobile libraries usually keep their books in a mini-bus. The back of the mini-bus has shelves for the books, and it is big enough for borrowers to step inside and look around. A driver takes the mini-bus to a certain place at a certain time, so people know when to expect it. They can then return their books and borrow some more.

    All Aboard the Library!

    A school in London didn't have space for a library inside the building. However, everybody agreed that it was still important to have a school library. So the head of the school, Graham Blake decided to park an old bus on the school car park and changed it into a library. Pupils helped to paint the bus, and after eight months, the new library was ready.