Recent research from the Pew Internet Project suggests that 90% of Americans aged from 12 to 17 use the Internet, and 51% of those teens use social networks. However, there are many possible problems with social networking sites and the teenagers who use them.

Apart from the social advantages, social networking sites can be used to record school research, develop artistic talents and experiment with other forms of subject creation. They provide a way to communicate with others who share the same interests and to get helpful advice on ongoing projects.
Along with these advantages come some dangers. For example, most social networking sites are open to all, especially MySpace, which is the most popular social network among teens in America. It means that they could be put in unpleasant and frightening situations.
A greater danger is that teens may become objects of the people with secret purposes. The secrecy of some social networking sites makes it easy for dangerous people to find young teens and invite them into dangerous conversations. It's easy for them to pretend as teens and draw children into dangerous real-world communication as well. Then further hurt might be on its way.
Another danger is identity stealing, which can happen when teens share too much information about their names, dates of birth and locations.
Therefore, it's very important to make sure teens are safe when they use social networks.
Many of the same rules that work for online chat work for these sites:
※Don't use your real name.
※ Don't give out personal information to people you don't know. A last name and a town are enough for a bad guy to find where you are.
※ Don't believe that people are who they say to be.
※ Immediately end any communication that makes you uncomfortable and report it to a parent.
Only if you are sure of your safety, can you enjoy the fun brought by social networking. Besides, trying to deal with all problems on your own can lead to terrible results. Remember, asking your parents or school officials for help doesn't mean you are unable to do anything but wiser than many others.

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.

    Different weather makes people feel different. It has an effect on health, intelligence（智力）and feelings.

    In August, it is very hot and wet in the southern part of the United Stated. People there have heart trouble and other kinds of health problems during this month. In the Northern and the Middle West, it is very hot at some time and very cold at the other times. People in these states have more heart trouble after the weather changes in February or March.

The weather can also influence intelligence. Fox example, in a 1983 report by scientists, IQ (智商) of a group of students was very high when a very strong wind came, but after the strong wind, their IQ was 10% lower. The wind can help people have more intelligence. Very hot weather, on the other hand, can make it lower. Students in many schools of the United States often get worse in exams in the hot months of the year (July and August).

    Weather also has a strong influence on people's feelings. Winter may be a bad time for thin people. They usually feel cold during these months. They might feel unhappy during cold weather. But fat people may have hard time in hot summer.  At about 18℃, people feel more comfortable.

    Are you feelings sad, tired, or unhappy today? It may be the weather's problem.

    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.

    What do you think the future will be like? Here are some answers from some students.

    Mary: Everyone will have a computer at home. There will also be many machines in the future. Then people will work only two or three days in a week.

    Jack: The weather in the future will be very hot. People can't live on the earth. They will have to look for (寻找) another planet to live on.

    Linda: I think the life in the future will be nice. There will be a lot of flowers and trees. And cities will look like parks.

    Henry: Every family will have a family doctor, so people will be seldom ill (很少生病) They will live to 120 years old.

    In recent years, there have been many breakthroughs in the AI (人工智能) field. Here, let us see four of the most interesting developments in AI in 2017.