Music is magic! Music speaks louder than words and it is a “language” that the whole world can understand. A piece of music can produce a response in the heart and mind. Like feeling an electrical current or receiving a personal radio signal, music has a spiritual effect on a person. Different kinds of music influence people in different ways.

    I have listened to music all my life. When I was twelve years old, the Beatles came to America and my whole world opened up. Maybe young people today cannot understand the influence of the Beatles when they exploded across America. Their influence changed the way we dressed, looked, acted and spoke... even our culture. The Beatles arrived in America from the UK just under three months after the assassination(暗杀) of President John Kennedy, which had put America into a great depression. And the freshness and lively spirit of the Beatles was exactly what the country needed to refresh itself.

    Music links the heart of the hearer with that of the composer. This means that it mixes the spirit of the composer with your spirit when you listen to it. And the music can take your spirit out of your body and transport you into another world. Music has a great way of touching people. Music can make you laugh, cry or shout. It's also a great source of inspiration.

    Try this one day and notice what happens: make yourself a cup of tea, sit on your sofa and play one of your favorite songs. Close your eyes, and soon you'll find yourself creating vivid mental images—matching the music that you are listening to.

    Do you love Beats headphones, True Religion jeans, and UGG shoes? These are some of the most popular brands (牌子) around. They are also expensive. But some experts say they are not much better than cheaper brands.

    For example, Jim Wilcox works for Consumer Reports. He tested all kinds of headphones. He says that $80 Koss Pro headphones provide basically the same quality (质量) and comfort as Beats. So why do people pay twice or even 10 times as much for the hottest brands?

    Experts say it's because fashionable, expensive brands send a message. Brands say “I belong” or “I can afford it.”

    Some people think that expensive brand names are worth the price. They say that some designer clothes really are top quality and that they last longer than cheaper brands. Some teenagers choose to wear popular brands because these brands make them feel good about themselves.

    Alexandra Allam, 17, likes to buy brand-name products. “I'd rather spend the extra money to get something I know I'll be satisfied with,” she says. Her friend Emmy Swan agrees, saying “As long as you can afford it, it seems reasonable to buy what you want.” But not all teenagers agree. “Spending hundreds of dollars for designer sunglasses is stupid and unreasonable,” says Daniel Steinbrecher, 16. “It's fake (假的) happiness.”

    People who are against wearing expensive brand names say that many designer brands aren't any better. “It's wasteful to buy things just because they are popular,” says Edmund Williams, 15. “You'll feel better if you buy things because you like them. If you have extra money to spend, it would be better to give it to people in need.”

    Every 30 seconds there is an earthquake. But don't worry because most are so weak that they cannot be felt. Only a few big ones hurt people.

    Many earthquakes happened in China, such as the big one is Sichuan last year. Thousands of people died in it. So it's important to know what to do when one hits. Here are some tips on how to stay safely in an earthquake.

    If you are indoors during an earthquake, hide under a desk. Stay away from windows and anything that could fall on you.

    If you are outdoors, move to a clear place. Try to be away from trees, signs, buildings and streetlights. These could fall on you.

    If you are in a shop and far from the door, don't try to run to outside and rush for exits(出口). Everyone will be doing that and you'll find it hard getting out. Don't get into a lift during an earthquake. Just hide under some strong covers near you.

    When an earthquake has ended, be careful because after-shocks may still happen. These are just as dangerous as the earthquake itself. So stay under the desk until you make sure it's safe to get up.

    If you are at home and you smell gas, open the windows and get out of the building as quickly as you can. A gas line in your house may be broken. This could be very dangerous.

    Metal-organic frameworks(MOFs) are compounds that are set to solve some tough challenges: producing water in the desert, removing greenhouse gases from the air and storing dangerous gases more safely.

    The Arizona desert is really dry. Anyone stuck in it without water would die from dehydration (脱水) within three days. Unless, that is, they had one of Omar Yaghi's next-generation water harvesters. Although daytime humidity(湿度)is only about 10 per cent, this rises to 40 per cent at night, which means there's enough water in the atmosphere to support life — if it can be transformed into liquid form.

    That's exactly what Yaghi's device does. It's a box about the size of a small microwave oven designed to suck the humidity from the air at night and turn it into drinking water the next day using only the heat of the sun as its power source. What makes it work is a special material called a metal-organic framework (MOF), which at normal temperatures attracts water molecules (分子) onto its surface of its internal pores(细孔). Warm it up and the water is released, each harvest producing one-third of a cup of pure drinking water.

    "With further improvements, a device, the size of a washing machine, could produce enough water for the basic needs of a household," says Yaghi, a chemist at the University of California. One-third of the world's population lacks safe drinking water; for them such a device could be a lifesaver.

    These crystalline cluster(结晶群)of metals, such as aluminum or magnesium, linked by organic molecules can be made into materials with an extremely high absorption ability, attracting specific molecules to their surface. In this way, MOFs cling to a variety of liquids and gases.

MOFs work thanks to their unique structure—large quantities of nanometer-sized internal spaces. In fact one MOF has so many pores that they would cover an area as large as six football fields. MOFs are also extremely stable light and have many different uses: their molecular structure can be varied to attract specific molecules, such as water, and their pores can be designed to best store them. Adding a small amount of heat or pressure causes the MOF to release what it is holding. More than 70,000 different MOFs have been produced to date for various applications.