Many people who work in London prefer to live outside it, and to go in to their offices or schools every day by train, car or bus, even though this means they have to get up early in the morning and reach home late in the evening.

    One advantage of living outside London is that houses are cheaper. Even a small flat in London without a garden costs quite a lot to rent (租住). With the same money, one can get a little house in the country with a garden of one's own.

    Then, in the country one can rest from the noise and hurry of the town. Even though one has to get up earlier and spend more time in trains or buses, one can sleep better at night and during weekends and on summer evenings, one can enjoy the fresh, clean air of the country. If one likes gardens, one can spend one's free time digging, planting, watering and doing the hundred and one other jobs which are needed in a garden. Then, when the flowers and vegetables come up, one has the reward of sharing the secret of Nature.

    Some people, however, take no interest in country things：for them, happiness lies in the town, with its cinemas and theatres, beautiful shops and busy streets, dance halls and restaurants. Such people would feel that their life was not worth living if they had to live it outside London. An occasional walk in one of the parks and a fortnight's (two weeks) visit to the sea every summer is all the country they want: the rest they are quite prepared to leave to those who are glad to get away from London every night.

    Most people know that listening to music when they are feeling down or depressed can encourage their spirits.

    However studies have also shown that music, especially certain tones can reduce stress. Music can change brainwave patterns, deepen breathing, and bring on a totally stress-free and more open mindset（心态）. Using music to relax when considering a particular problem may not only raise your mood, but also could help you reach that "a-ha"moment and find a solution.

    Music has also been shown not only to make you feel good, but also, to be a great motivator. For example, during exercise, listening to music can keep you going, or get you to exercise more by helping you to ignore negative feelings of tiredness and focus on the pleasurable feelings you get from being absorbed in the music.

    Music is mainly used to record emotion. When we listen to a piece of music we share the artist's feelings on a visceral（本来的）level. That can be sad, and who among us hasn't put on a painful love song to share in the misery after a bad break-up? On the contrary, we can share in the delight of songs of joy and happiness, or any song or piece of music that reminds us of a particular happy time in our past.

    So next time you are feeling down, put on Beethoven' s Ode to Joy, I bet you will feel a lot better about whatever it was that was bothering you!

    You're rushing to work and a man ahead of you collapses on the sidewalk. Do you stop to help? In a study of by-standers, it was found that some people avert their gaze and keep on walking rather than stop and get involved.

    "There is a tendency to decide that no action is needed." says a psychologist. "The first thoughts that pop into your mind often keep you from offering help. In order to take action, you have to work against them. " Here are some common thoughts that might prevent you from helping.

    Why should I be the one? I'm probably not the most competent (有能力的) person in this crowd. You might think someone older or with more medical knowledge should offer assistance.

    What if he doesn't really need my help? The fear of embarrassment is powerful; no one wants to risk looking foolish in front of others.

    No one else looks concerned—this must not be a problem. We can follow the people around us, but most people tend to hold back their emotions in public.

    "If you spot trouble and find yourself explaining inaction, force yourself to stop and assess the situation instead of walking on," says the psychologist. "Then retry to involve other people; you don't have to take on the entire responsibility of being helpful. Sometimes it's just a matter of turning to the person next to you and saying, 'It looks like we should do something.' Or asking someone if an ambulance has been called and, if not, to call for one. Once you take action, most people will follow you."

    Most groups of plants and animals are richer in species and more plentiful near the equator. In the ocean, that holds true for cold-blooded predators(掠食者). But warm-blooded predators are more diverse toward the poles and noticeably missing from several warm hot spots. Why?

    John Grady, an ecologist, and his team considered the possibility—warm-blooded animals need a lot to fuel their metabolism(新陈代谢). Perhaps colder waters are just richer in small fish? But they found that at higher, colder places, there isn't actually much more food around. It's more that warm-blooded animals are eating a much bigger share of it than their cold-blooded competitors.

    The real explanation is simple. An animal's speed, swiftness, and intelligence depend on its metabolism, which in turn depends on its temperature. Since birds and mammals can keep heating their bodies in icy conditions, they remain fast and attentive. By contrast, the fish they hunt become slower and duller. At some tipping point of temperature, seals, dolphins, and penguins start out swimming their prey(猎物). They become more likely to come upon targets and outpace the cold-blooded predators of their own.

    In Grady's words, "Warm-bodied predators are favoured where preys are slow, stupid and cold." That's why sharks and other predatory fish dominate near the equator, but colder waters are the kingdom of whales and seals. By keeping food to themselves in the poles, these creatures can then specialize on specific types of prey, which makes them more likely to split into separate species. The killer whales of the North Pacific, for example, include mammal-eating transients and fish-eating, year-round residents.

    But the world is changing. It's likely that the surface of the oceans will warm by 2 to 3℃ within this century. Grady's team estimates that every time the ocean's surface warms by 1℃, populations of sea mammals will fall by 12%, and populations of seals and sea lions will fall by 24%.

    But "predictions are hard," Donna Hauser from the University of Alaska Fairbanks notes. "Polar bears are losers of a warming world, but some populations are still doing well. Some groups of whales have changed the timing of their migrations; others are hunting in deeper, colder waters. These changes might make sea mammals more adaptable to changing climates. Maybe they just need to find the places where fish remain slow, stupid and cold."

    Londoners are great readers. They buy vast numbers of newspapers and magazines and of books-especially paperbacks, which are still comparatively cheap in spite of ever­increasing rises in the costs of printing. They still continue to buy "proper" books, too, printed on good paper and bound (装订) between hard covers.

    There are many streets in London containing shops which specialize in book­selling. Perhaps the best known of these is Charring Cross Road in the very heart of London. Here bookshops of all sorts and sizes are to be found, from the celebrated one which boasts of being "the biggest bookshop in the world" to the tiny, dusty little places which seem to have been left over from Dickens' time. Some of these shops stock, or will obtain, any kind of books, but many of them specialize in second­hand books, in art books, in foreign books, in books on philosophy, politics or any other of the countless subjects about which books may be written. One shop in this area specializes only in books about ballet!

    Although it may be the most convenient place for Londoners to buy books, Charring Cross Road is not the cheapest. For the really cheap second­hand books, the collector must venture off the beaten track, to Farringdon Road, for example, in the East Central district of London. Here there is nothing so impressive as bookshops. The booksellers come along each morning and pour out their sacks of books onto small handcarts. And the collectors, some professionals and some amateurs, have been waiting for them. In places like this they can still, occasionally, pick up for a few pence an old one that may be worth many pounds.

    Since 50 years ago, scientists have been searching for ways to link the brain with computers. Brain Computer Interface (BCI) technology could help people with disabilities send commands to machines.

    Recently, two researchers, Jose Millan and Michelle Tavella from the Federal Polytechnic School in Lausanne, Switzerland, demonstrated (展示) a small robotic wheelchair directed by a person's thoughts.

    In the laboratory, Tavella operated the wheelchair just by thinking about moving his left or right hand. He could even talk as he watched the vehicle and guided it with his thoughts.

    "Our brain has billions of nerve cells. These send signals through the spinal cord (脊髓) to the muscles to give us the ability to move. But spinal cord injuries or other conditions can prevent these weak electrical signals from reaching the muscles," Tavella says, "Our system allows disabled people to communicate with external world and also to control devices."

    The researchers designed a special cap for the user. This head cover picks up the signals from the scalp (头皮) and sends them to a computer. The computer interprets the signals and commands the motorized wheelchair. The wheelchair also has two cameras that identify objects in its path. They help the computer react to commands from the brain.

    Prof. Millan, the team leader, says scientists keep improving the computer software that interprets brain signals and turns them into simple commands. "The practical possibilities that BCI technology offers to disabled people can be grouped in two categories: communication, and controlling devices. One example is this wheelchair." He says his team has set two goals. One is testing with real patients, so as to prove that this is a technology they can benefit from. And the other is to guarantee that they can use the technology over long periods of time.