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.

    Since ancient times, human beings have looked up at the night sky. Comets (彗星) and meteors (流星) flying through the blackness were seen as signs from the gods. They were used to tell the future of human lives.

    In 2013, a meteorite shower hit an area in Russia. It injured around 1,200 people. In ancient times, this would have been a strange and terrible experience. Today, thought, science offers simple explanations for the occurrence (事件).

    Meteorites are small pieces of debris (碎片) that float around in space. Sometimes, they come near a planet, such as Earth. When they enter our atmosphere, they often heat up and become very bright. This is why they are sometimes called “fireballs”. They are usually made of metals, such as iron (铁), and other minerals (矿物). The Russian meteorites were stony, with iron making up 10 percent of them.

    Meteorite showers, such as that in Russia, happen when a large meteor enters the Earth's atmosphere and, due to heat, breaks up into small parts. Most of these are very small — smaller than a grain of sand — and so don't even make it to the ground. But others can cause a lot of damage.

    The meteor in Russia weighed 10 tons when it entered our atmosphere, and broke up about 20-30 miles (30-50 km) above ground. The sky was filled with bright lights and loud noises. Many windows were broken. The damage cost Russia around 206 million yuan.

E

    Maybe you know floods, earthquakes, sandstorms and so on. But did you hear of typhoons(台风)?

    Typhoons are some of the worst storms, usually around the Pacific Ocean（太平洋） and the South China Sea. Most happen in July, August and September.

    How does a typhoon happen? When lots of sea water gets hot in the summer sun, it evaporates （蒸发）into the air. This makes the air hotter. When the air gets warm enough, it starts to move higher up into sky. Then cooler air around it rushes in. It fills the space that is left. After the air gets warmer, it starts to move quickly, making wind. The wind goes in circles（圆圈）and it keeps moving higher in the sky. The warmer the air gets, the quicker the wind moves. And when the wind moves faster than 30 meters a second, a typhoon begins.

    A typhoon has two parts, one is called the “eye”. In the eye, the wind does not move so fast. The other part is the wall of clouds around the eye. Here are the strongest winds and hardest rains.

    Typhoons are very dangerous. In November this year, Typhoon Haiyan killed 5500 people in Philippines. More people are missing（消失）.

    What to do when a typhoon hits（袭击）?

⒈Stay inside. Close all the windows and stay away from them.

⒉Try to bring all of your things inside. Strong winds could even blow away your bikes!

⒊Listen to the radio or TV for important information.

⒋If you're told to go to a safer place, do it right now.

    Workers wear them. Swimmers wear them. Scientists wear them. Woodcutters wear them. People who play sports wear them. Goggles protect the eyes. They keep out water and chemicals. They keep out bits of wood or stone. They might look funny, but goggles do serious work!

    Why do people need to wear goggles? They need to keep the can hurt our eyes. Have you ever gotten a piece of sand or dirt or other small particle in your eye? What happens? It hurts. Your eye begins to fill with tears. Those tears are your body's way of getting the sand or dirt out of your eye. Sometimes this works. Your eye feels much better.

    But what happens if your tears don't work? What happens if the piece of sand has gotten stuck in your eye? Eyes are delicate. They can be scratched or cut easier than skin(皮肤). If the particle is not washed out by tears, you might have to go to the doctor. You could even have problems seeing out of that eye.

    Instead of waiting to see if tears will help, some people use goggles. This can prevent things from getting in their eyes at all. If they use goggles. Their eyes are protected from the things that can cause problems, Goggles are a better way to protect eyes. They are made of plastic or glass, and they are tied around your eye area. Some of them hook behind your ears like glasses. Other goggles have a strap (带子) that goes around your head. Both kinds stay right where you put them until you take them off. That way, you can use both hands to work or play sports, and you don t have to worry about something getting in your eyes.

    Your eyes are safe, and you can get busy working or playing!

E

    Artificial intelligence（人工智能）, or AI in short, is the science of giving computers and machines ability to think and work like humans. AI scientists and engineers have made a lot of cool technologies.

    AI is rapidly catching up with the human ability to read faces. As a result, facial recognition（识别）is used a lot in the world. Chinese police use this technology to identify criminals（罪犯）.Once they caught a criminal when he attended a concert. It also checks the ID of ride-hailing（网约车）drivers and lets people pay for things with a smile.

    AI is also used in self-driving cars, which are believed to be the future of driving. Most drivers may wave or nod at passers-by to let them cross the street, but self-driving cars don't have this ability. Carmakers are testing a light signal system to help them "speak" to humans. The system can show what self-driving cars will do. For example, if a driverless car is yielding（让路）, it will flash two white lights side to side. A rapidly flashing light tells passers-by that the car is about to speed up.

    Service Robots also show you know powerful AI is. Imagine this—you come back home from school and your robot housekeeper is waiting for you at the door. After dinner, he teaches you to play the piano, just like a real music teacher. Such thoughts will soon happen in the real world. In the future, more and more service robots will become good home helpers.

    AI is so powerful that it can help human beings and even replace us in many jobs.

    Space vegetables are grown from seeds(种子) that have been taken to space and brought back to the earth. The seeds are affected by the radiation(辐射)and low gravity in space. When they are brought back to the earth, these seeds produce vegetables that are bigger and healthier than normal vegetables. However, some people worry about eating space vegetables. They think that space vegetables might not be good for us and could make us get sick because of the radiation in space. However, people should not be frightened because space vegetables are very healthy.

    Here are some facts that you should know about space vegetables.

Space vegetables are grown from seeds that are carefully chosen. When seeds are brought back from space they are tested to make sure that they will be safe to eat.

    Space vegetables are better for you than normal vegetables. For example, space tomatoes stay fresh for twenty days, which is one week longer than normal tomatoes。

    After genetically modified (转基因)food appeared in the market, people worried that they were eating unknown things. For example, if nut genes(坚果基因) are put inside potatoes, people allergic(过敏的) to nuts might get sick from eating these potatoes because they do not know they are also eating nuts. Unlike genetically modified food, space vegetables have not been genetically changed. This means that no new genes are put into the vegetables. Therefore, there are no dangers of eating unknown.