Every year, millions of birds are killed or hurt when they fly into buildings. Why does this happen?  Birds are flying into windows and tall buildings that are all covered by glass.

Many birds fly from one place to another. Most of the time, they live in the wild, such as forests and wetlands.  They might see small trees and flowers inside a window and want to rest on these plants. The birds do not know there is glass between them and the plants.  

Some birds fly at night. They use the moon and stars to help guide them in the right direction. Tall buildings with lights on at night can confuse（迷惑）the birds.  The birds see the light, but they cannot tell that the light is coming from inside a building. They fly toward the light and crash into a building. On many mornings, there might be several dead birds lying on the ground.

  Many office buildings now turn off their lights at night. This helps reduce the number of birds that fly into buildings and it also helps save energy.

Do you have difficulty falling asleep at night? If so, here is a piece of advice for you—listen to some soft music.

Scientists have found that soft music can help improve sleep quality and quantity. It works for people of all ages.  Soft music can help us fall asleep faster, wake up less during the night and feel more rested in the morning. You may not notice the effects overnight, though. It could take as many as three weeks to see any improvements.

The reason aren't clear yet. It may have something to do with the relaxing effect of a good song. Music can have real physical effects, too. Soft music can lower our heart rate and slow down our breathing.

Scientists say that for most people, music that has 70 beats per minute (bpm) works best. Classical, jazz and folk music are usually more effective than other musical styles.  You may need experiments to make your own playlists. If you are not sure how many beats a song has in a minute, you can find out by entering its title into songbpm. com. And remember to get the volume (音量) right. Make sure that the final piece is one that slowly fades out (渐弱).  

It is very necessary to get enough high-quality sleep. Before you go to bed tonight, play some soft music. Then, just prepare to be rocked off to dreamland!

A．This prepares us for sleep.

B．Familiar songs work well, too.

C．Why can soft music help us sleep better?

D．If not, you may be woken up by the sudden silence.

E．And it works much better for people with sleeping problems.

There are more than 35 million teenagers who are between the ages of 13 and 19. They want to be free and independent. Many teenagers disagree with their parents about how much freedom they should have. Some disobey their parents. 

Today American teenagers spend a lot of money buying records，clothes and electronic devices. Last year teenagers spent almost 100 thousand million dollars. Where do the American teenagers get all this money？Many of them have part﹣time jobs. Some work as baby﹣sitters. They make about 4 dollars an hour. Some teenagers do not have jobs. Instead，they receive money from their parents. They might get as much as 20 dollars a week. 

There is an English saying,"Laughter is the best medicine. " Until recently, few people took the saying seriously. Now however, doctors have begun to look into laughter and the effects it has on the human body. They have found that laughter really can improve people's health.

Tests were carried out to studythe effects of laughter on the body. People watched funny films while doctorschecked their heart, blood pressure, breathing and muscles. It was found that laughter has similar effects to physical exercise. It increases blood pressure, makes the heart beat quicker and makes people breathe deeper; it also works several groups of muscles in the face, the stomach, and even the feet. If laughter exercises the body, it must be beneficial. 

Other tests have shown that laughter appears to be able to reduce the effect of pain on the body. In oneexperiment doctors produced pain in groups of students who listened todifferent radio programmes. The group that tolerated (忍耐) the pain for the longest time was the group which listened to a funny programme. The reason why laughter can reduce pain seems to be that it helps to produce a kind of chemical in the brain which diminishes both stress and pain. 

As a result of these discoveries,some doctors in the United States now hold laughter clinics, in which they help to improve their patients' condition by encouraging them to laugh. They have found that even if their patients do not really feel like laughing, making them smile is enough to produce beneficial effects similar to those caused by laughter.

There is a fish called the angelfish （神仙鱼），which can change from female to male. No，it cannot do it by simply wishing to become male. The change happens for a speeifie reason. 

The angelfish live in groups. And each group has one male fish，which is blue in colour，and four female fish，which are yellow in colour. 

The male angelfish is the strongest and largest member of the group. When the male fish dies，the largest female fish in the group begins to change its looks. She begins to grow larger in size. After a week，she starts changing colour，from yellow to blue. Slowly，she begins looking like a male. Two weeks later，black stripes （条纹） appear on her body. She is now really male. 

The angelfish are among the most brightly coloured fish of the sea. People prefer to keep them because of the interesting patterns （图案） on them. People like to keep them because of their good looking. Often，the young ones have different colours from the old ones. At night their colours may change. 

Sharing Mind Maps with Classmates

There are different kinds of mind maps. You can choose from them to complete the tasks clearly.

Every year, millions of birds are killed or hurt when they fly into buildings. Why does this happen?  Birds are flying into windows and tall buildings that are all covered by glass.

Many birds fly from one place to another. Most of the time, they live in the wild, such as forests and wetlands.  They might see small trees and flowers inside a window and want to rest on these plants. The birds do not know there is glass between them and the plants.  

Some birds fly at night. They use the moon and stars to help guide them in the right direction. Tall buildings with lights on at night can confuse（迷惑）the birds.  The birds see the light, but they cannot tell that the light is coming from inside a building. They fly toward the light and crash into a building. On many mornings, there might be several dead birds lying on the ground.

  Many office buildings now turn off their lights at night. This helps reduce the number of birds that fly into buildings and it also helps save energy.

Connecting with Nature

How do you feel when you hear birds singing freely in the trees? What's your feeling when you see butterflies dancing slowly and lightly in the wind? Whether you love researching the outdoors or watching far away, getting close to nature can take your mind off your worries and make you feel relaxed.

What is nature?

Nature means the world around us that is not man-made, including birds, mountains, trees, the sea and the stars. It's also a force that controls things like weather. We can find nature wherever we are and wherever we go —beaches, gardens, parks, rivers, and even unexpected places like cracks (裂缝) in the stones.

Why does nature make us feel good?

Spending time in nature brings peace, joy and wonder to our lives. It takes us outdoors, gets us active and lets us care more about the environment. Even a little gift of nature can make us feel free and hopeful, such as breathing in fresh air, listening to the wind in the trees or standing at a mountain. Ralphie, who is 10, likes being close to nature on a bike with his family. He says, "It makes us feel happy and takes our mind off things because we have to pay attention. We are away from traffic and we hear more birdsong and see more wild animals."

How can we feel closer to nature?

Feeling closer to nature is easy. We can build a connection with nature wherever we are using our senses. Try listening closely to birdsong, smelling flowers and feeling sand between our fingers. Paint a picture and take photos of the natural places that we like best. They may help us feel closer to the natural world. It's important to try and connect with nature, notice its beauty and how it makes us feel.

The invention of barcodes (条形码) is based on a very simple idea. We only need to give each product a specific number and print it.  We could simply print the number itself. But this can cause problems. For example, an unclearly printed "seven" could look like a "one" to a computer. It's also true for "three" and "eight".  We need a better way of printing numbers so that they can be read correctly at high speeds. That's the problem barcodes solve.

Each number in a barcode is shown by seven blocks of the same size.  For example, the number "one" is shown in turn by two white stripes (条), two black stripes, two white stripes, and one black stripe. 

A barcode includes different parts and each one provides a specific meaning. The first part of a barcode tells you the country where the product was made. For example, 690—692 is the barcode for China. The final part is about the product itself. This is how barcodes work.