Are you shy? If you are, you are not alone. In fact, close to 50 percent of people are shy. Almost 80 percent of people feel shy at some point in their lives. These days, shyness is becoming more and more common. Now, scientists are trying to understand shyness. They have some interesting ideas about why people are shy.

Is it possible to be born shy? Many scientists say yes. They say 15 to 20 percent of babies behave shyly. These babies are a little quieter and more watchful than other babies. Interestingly, these shy babies usually have shy parents. As a result, scientists think that some shyness is genetic.

Family size might cause people to be shy as well. Scientists at Harvard University studied shy children. They found that 66 percent of them had older brothers and sisters. As a result, they became shy. At the same time, children with no brothers and sisters may be shy as well. Growing up alone, they often play by themselves. They are not able to learn the same social skills as children from big families.

You may also be shy because of where you were born. When scientists studied shyness in different countries, they found surprising differences. In Japan, most people said they were shy. But in Israel, only one of three people said so. What explains the difference? One scientist says the Japanese and Israelis have different opinions of failure. In Japan, when people do not succeed, they feel bad about themselves. They blame（责备）themselves for their failure. In Israel, the opposite is true. Israelis often blame failure on outside reasons, such as family, teachers, friends, or bad luck. In Israel, freedom of opinion and risk taking are strongly supported. This may be why Israelis worry less about failure and are less shy.

For shy people, it can be difficult to make friends, speak in class, and even get a good job. But scientists say you can get over your shyness. They suggest trying new things and practicing conversation. And don't forget—if you are shy, you are not the only one.

    Sharks (鲨鱼) are the most frightening animals in the sea. Sometimes we can see sharks swimming in the sea around Hong Kong. People put nets around some beaches to protect swimmers. When there is a "shark's flag", people must stay on the beach. It will be too late if a shark can swim sixty kilometers an hour to you.

    There are 30 kinds of sharks and 25 kinds of them are dangerous. The whale sharks are very big. They can grow to 18 meters long, but they are not dangerous to people. The jaws (大白鲨) and the tiger sharks are the most dangerous kinds of sharks.

    Do you know all sharks must keep swimming, or they will go down? All sharks can feel everything that happens around them. We must keep calm and don't make any noise when a shark is swimming near you.

    If a shark loses a tooth, a new one will grow out very quickly. So sharks always have many sharp teeth.

    As space science develops, man has learnt more and more about space. Space is not only amazing but also dangerous. While working in space, spacemen are facing danger as well as success.

    Scientists have found out that the radiation is the greatest danger to spacemen in space. When spacemen are working in space, they are in danger of the radiation from the Sun and other stars, which is bad for their health.

    Space rubbish is also a great danger to spacemen. It's reported that there were 9,000 man-made things flying in space. About 30% of these are satellites, 10% are spaceships, and the rest space rubbish. A small piece of these can knock a spaceship window and cause some damage.

    Scientists are watching and reporting any possible danger all the time. They are working to deal with space rubbish. Although space is really dangerous, it interests many people on Earth. In the near future, it may become possible for people to spend a few days in a space hotel. We may even choose to leave the Earth and live in space in a few years. So we should do something to help improve the space environment.

    When you are waiting on a phone call with a pen in your hand or feeling bored on a train, you may probably doodle(涂鸦). Consultant Graphology(笔迹咨询师)Tracey has studied the most common doodles and their meaning in a new piece of research. Here she shares the psychology(心理学)behind those doodles.

    A black hole is a place in outer space with very strong gravity. Gravity is a great force(力量) that shapes the universe. On Earth, gravity makes apples fall from trees. It keeps your feet planted on the ground. The gravity in a black hole is much stronger. It is so strong that nothing around it can get away from it, not even light.

    Black holes are invisible. We can't actually see them because they don't throw back light. But scientists can find them with space telescopes(望远镜)and special tools. The strong gravity makes nearby stars move in a certain way. By studying how the stars move, scientists can find out if they are flying around a black hole. Strange things happen around black holes. This makes black holes a popular subject of science fiction(科幻)stories, although they are very real.

    A black hole forms when a star dies. The star falls in on itself and turns into a very small point. Because of its small size and huge mass(质量), the gravity will be so strong that it will pull light in and become a black hole. Black holes can grow huge as they continue to pull other things in and "eat" them. Many scientists believe that there are super-massive black holes at the center of galaxies, including the Milky Way.

    The idea of the black hole was first suggested by two different scientists in the 18th century: John Michelle and Pierre-Simon Laplace. In 1967, a physicist named John Archibald Wheeler came up with the name “black hole". Studying black holes can tell us many things about our galaxy and help scientists answer questions about the universe.

    Owls live in almost every country in the world. Most owls don't sleep at night. When they fly, you can't hear them. They are very quiet. Owls are good at hunting（捕猎）. They eat a lot of things such as mice, snakes, small birds and even fish. Owls have very good hearing. That helps them to hunt well in dark places. Their eyes are special. Both of their eyes face front. They can see very far away. There are facial disks(面盘) around their eyes. These facial disks can help with their hearing. Owls can turn their heads 270°. That helps them see what's going on all around them.

    Maybe because owls look a little different and have special life habits. There are a lot of stories about them. Some cultures believe that owls are very clever and some cultures think owls may bring bad luck to people. In fact, owls are really good friends of people. They eat lots of mice every year. That helps save a lot of food for people. But the number of owls in the world is becoming smaller and smaller because of people's activities. Now owls are protected by law(法律) in many places of the world. For example, in some places, people can't keep an owl as a pet at home.