Parents often believe that they have a good relationship with their teenagers. But last summer, Joanna Henry noticed a change in their older son: suddenly he seemed to be talking far more to his friends than to his parents. “The door of his room is always closed,” Joanna noted.

    Tina and Mark noticed similar changes in their 14-year-old daughter. “She used to cuddle up (蜷伏) with me on the sofa and talk,” said Mark. “Now we joke that she does this only when she wants something. Sometimes she wants to be treated like a little girl and sometimes like a young lady. The problem is to find out which time is which.”

Before age 11, children like to tell their parents what's on their minds. “In fact, parents are first on the list,” said Michael Riera, writer of Uncommon Sense for Parents with Teenagers. “This completely changes during the teen years.” Riera explained. “They talk to their friends first, then maybe their teachers，and their parents last.”

Parents who know what's going on in their teenagers' lives are in the best position to help them. To break down the wall of silence, parents should create chances to understand what their children want to say, and try to find ways to talk and write to them. And they must give their children a mental (精神的) break, for children also need freedom, though young. Another thing parents should remember is that to be a friend, not a manager(管理者), with their children is a better way to know them.

    The word “day” has two meanings. When we talk about the number of days in a year, we are using “day” to mean 24 hours. But when we talk about day and night, we are using “day” to mean the time between sunrise and sunset. Since the earth looks like a ball, the sun can shine on only half of it at a time. Always one half of the earth is having day and the other half night. A place is moved from day into night and from night into day over and over by the spinning(旋转) of the earth. At the equator(赤道) day and night are sometimes the same length. They are each twelve hours long. The sun rises at 6 in the morning and sets at 6 in the evening. For six months the North Pole is tilted(倾斜) toward the sun. In those months the Northern Hemisphere(半球) gets more hours of sunlight than the Southern Hemisphere. Days are longer than nights. South of the equator nights are longer than days. For the other six months the North Pole is tilted away from the sun. Then the Southern Hemisphere gets more sunlight. Days are longer than night. North of the equator nights are longer than days. Winter is the season of long nights. Summer is the season of long days.

    Songs help memories

    The power of music

    Most people can remember important news stories clearly, whether it was the murder of President Kennedy in the US or 9/11.But now psychologists Martin Conway and Catriona Morrison, from the University of Leeds in the UK, are investigating how music can create “autobiographical memories” of the main events in our lives. The study is online. People have to choose a song by the Beatles and describe the memories that they have when they listen to it.

Reminiscence bump

    Morrison explained that they looked at different age groups and their memories. We often remember more from when we are teenagers and this is called “the reminiscence bump”. This is the time in your life when you form your idea of who you are. For older people who have memories related to the Beatles' music, most of those memories are from when they were teenagers. But younger people also had clear personal memories from their past.

    She loves you

    This study was different from other memory studies, because people remembered events from their past with lots more details. Morrison explained:     “It was like people had travelled back to the past, and they had very clear memories of things that had happened. When they heard a song like She Loves You by the Beatles, they could remember one night in autumn 1963.They remembered what they were wearing, what the weather was like and what their friend said to them. You get a lot more information than if you just say, ‘tell me about a night you remember'. ”

    The study has found that music could be used with people who have problems remembering the past. “You could use music to help improve people's ability to remember,” said Morrison. “In the future, we would like to do more experiments to see how useful music is in helping people to remember the past, and compare it to other things that might also help.”

    Is human blood all the same? "Sure," you may say. "It's all red." Well, it's not as simple as you might know. Blood is made up of different pans, such as red blood cells, white blood cells, and platelets (血小板). Two chemical molecules (分子) on the red blood cells make people's blood different. Scientists mark one molecule "A" and the other molecule "B".

    According to which and how many molecules are on the red blood cell, scientists divide blood into four types: A, B, AB and O. Your blood type will stay the same through your whole life. Scientists have been wondering if there are some links between people's blood type and their personalities (个性), but they don't know for sure. Some say that people with the same blood type may have things in common.

    What's your blood type? Does your friend have the same blood type as you? Read the following.

    People with type A: They look peaceful from the outside. But they ask so much of themselves that they may be very agitated inside. They become happy or sad easily. Sometimes they are shy but always very careful. They can easily win people's trust.

    People with type B: They have strong minds. Once they begin a task and make up their minds to do it, they will not give up easily. They'll try their best to finish it and do it well. They always try to make themselves different from others. They want to do things in their own way.

    People with type AB: Maybe they are the strangest among all blood types. They can be both open and shy, noisy and quiet at the same time! They are responsible and always ready to help others.

    People with type O: They're open and good at making friends. They always begin tasks but don't always finish them in the end. They have lots of new ideas and love to be the centre of attention. They always strongly believe in themselves.

    Last year, a special kind of glove came out. It was invented to help blind people to learn Braille, which is a special system for the blind to read by touching. Shaking motors (震动马达) are put on each finger of the glove. They can make different sounds to tell a user which letter he is touching. Recently, two British college students have invented another special glove for the blind. It can make the user feel small and quick movements. An ultrasonic sensor (超声波传感器) with a battery is put on the back of the glove. When the user wearing the glove is close to an object(物体), ultrasonic waves (超声波) from the glove are sent out (发出). As soon as they hit the object in front, the waves will return to the glove. Then the waves cause the glove to shake. And the ultrasonic sensor makes different kinds of sounds. The sounds make the user know how far he is from the object.

    In the college invention competition, the two students got first prize and won 1,540 pounds. One of the designers said, "Now the ultrasonic sensor on the glove is quite large. We're going to use the money to develop a smaller and lighter ultrasonic sensor."