Do you notice music playing there when you go somewhere? Today most stores, stations restaurants and other places play music. You might even hear music in an office or on a farm.

Scientists believe that music changes the way people behave. They think that Western classical music makes people feel rich. When a restaurant plays classical music, people spend more money on food and drinks. When the restaurant plays modern music, people spend less money. Without music, people spend even less.

Scientists also believe that loud, fast music makes people eat faster. In fact, people eat their food faster when the music gets faster. Some restaurants play fast music during their busy hours. This gets people to eat faster and leave more quickly. Restaurants can make more money this way.

Some scientists think that music makes people think and learn better. They say that music helps students be more active. It is true that people learn better when they are relaxed. And listening to music can help people relax.

    Next time you hear music somewhere, be careful. It might change the way you do things.

    What will man be like in the future — in 5,000 or even 50,000 years from now? We can only make a guess, of course, but we can be sure that he will be different from what he is today. For man is slowly changing all the time.

Let us take an example. Man, even five hundred years ago, was shorter than he is today. Now, on the average, men are about three inches taller. Five hundred years is a relatively (相对地) short period of time, so we may suppose that man will continue to grow taller.

    Again, in the modern world we use our brains a great deal. Even so, we still make use of only about 20% of the brain's capacity (容量.) As time goes on, however, we shall have to use our brains more and more and finally we shall need larger ones! This is likely to bring about a physical change too. The head, especially the forehead, will grow larger.

    Nowadays our eyes are being used too much. In fact, we use them so much that very often they become weaker and we have to wear glasses. But over a very long period of time it is likely that man's eyes will grow stronger.                      

    On the other hand, we tend (有…的趋势) to make less use of our arms and legs. These, as a result, are likely to grow weaker. At the same time, however, our fingers will grow more sensitive (敏感的) because they are used a great deal in modern life.

    What about hair? This will probably disappear from the body altogether in course of time because it does not serve a useful purpose any longer. In the future, then, both men and women are probably to be hairless!

    Perhaps, all this gives the impression that future man will not be a very attractive (有吸引力的) person to look at! This may well be true. All the same, besides these changes, future man will still have a lot in common with us. He will still be a human being, with thoughts and feelings similar to our own.

    Imagine one day, the water taps (水龙头) in your house stop running. You have to buy water from shops. And still there isn't enough for everyone. Your mother has to save the family's shower water to do other things. Would you be able to stand that kind of life?

    Probably not. But that's what kids in Yemen are experiencing. Experts said Yemen is going to be the first country in the world to run out of water. According to a report, the capital, Sana, will run out of drinking water as early as 2025.

    Because of the shortage, the government often cuts the water supply(供应). Hannan, an 18-year-old from Lahej, told Times, "In a good week we'll have a water supply all week. But then the following week there will be water only for a day or two."

    Hannan said only rich people have enough water to use. They can buy water from the shops or from the water trucks. Private companies own the trucks. They travel around the city every day to sell water—at very high prices. "A lot of people can't afford it," she said.

    The average(平均) person in Yemen uses 100 to 200 cubic(立方) meters of water per year. That is far below the international water poverty(贫困) line of 1,000 cubic meters.

    The government is thinking of making use of seawater. But it will cost a lot and it may not happen soon enough to help the people of Yemen.