As children begin to head back to school, there are several things that you can do to make sure that your child stays healthy and performs at their peak potential during the school year.

    1). Make sure your child is up to date on their immunizations(免疫). The summer is a good time to schedule visits to the doctor's as your child is not in school, and the visit won't require that your child miss school days.

    2).Encourage proper nutrition. America faces childhood obesity(肥胖). This means that the percentage of overweight children is increasing each year, and this will place your child at risk of developing a variety of diseases when they are middle age or even young adults. You can start helping your child to become healthier by offering fruits and vegetables at home instead of calorie heavy potato chips and candy.

    3). Get your child involved in sports activities. Activities in high school such as track and cross-country are important for socialization for your child, as well as helping to improve their health. You can get your child interested in wholesome activities by discussing with them how you enjoyed similar activities in high school.

    4). Have the birds and the bees conversation with your child. Many children become sexually active in junior school and senior high school, and the sooner you discuss sex with your child the sooner they will be prepared. Tell your child that there is always the possibility of infecting a sexual disease when two people have sex; and discuss with your child the use of condoms. The sooner you start having this embarrassing situation the better.

    5). Know your child's friends. You can do this by inviting your child to bring their friends over to your house for a pizza night, or by chatting with them when they stop by your house. If you find your child's friend has a bad reputation, then you could consider introducing your child to a different network of people, such as through the girl/boy scouts. Forbidding your child from seeing a certain person may only lead them to rebel and become closer to that person.

    6). Discuss with your child the seriousness of drug use and abuse. Your child may not realize that using drugs can have serious consequences. Your child may get the false impression that drug use is his right. Explain to a child that saying no to drugs is their right, and that anybody offering them drugs is not their friend.

    7). Help your child to avoid a life long smoking addiction by discussing with them the consequences of smoking. The sad fact is that most smokers became addicted when they were in their teenage years, and are unable to quit for long periods of time and often die many years earlier due to their smoking habit which increases the risk of lung cancer, heart disease, and a variety of medical conditions. Even if you are a smoker yourself, you can discuss with your child about how damaging smoking can be on a person's health.

    8). Impress upon your child the importance of traffic rules. Tell them that it is OK to wear a seat belt in anyone's car, because it may save their life one day. If your child rides a bicycle or a skateboard, then discuss with them the importance of always wearing a helmet. As you child becomes qualified for driver's permit, you should discuss with them the importance of prevention from drinking and driving.

    9). Be cautious about signs of depression in childhood. A surprisingly large number of children may become depressed, and a small number of teenagers and children commit suicide(自杀) each year. Realize that any signs of unusual depressed mood, angry outbursts, suicidal comments, feelings of hopelessness, and loss of enjoyment of activities with friends may be signs of depression.

    One of the most recent social changes taking place in the world is social networking. Social networking has been in existence for at least 150 years, and probably longer than that. In the times before the invention of the computer and the World Wide Web (WWW), social networking was done in person. People who had similar likes and interests would gather together to share experiences, make new friends, and improve their businesses.

    On the Internet, social networking websites made their first appearances during the late 1990s. The first major social networking website in the United States was MySpace. MySpace allowed its users to exchange messages, share pictures, and make new friends in a way that was never thought of in the past. With MySpace, people who did not go out much could reach out to others from their own homes.

    In 2004, Facebook was created. It was first a website created for use by Harvard University's students and teachers, but it soon expanded to include just about everyone. It is now larger than some of the largest companies in the world. It is a website that is changing all the time. Facebook has completely changed the way people stay connected with each other and the rest of the world. The way it works is simple. Users can set up a new account (账户) easily. All a new user needs is an email address to start. Once a person has created an account and his friend also has his own Facebook page, he can invite his friend by sending a request out to him. Once you get started, making new friends will come easily.

    Here is a record of the discussion about AI (artificial intelligence) conducted by several scientists:

    Scientist A: I would say that we are quite a long way off developing the AI, though I do think it will happen within the next thirty or forty years. We will probably remain in control of technology and it will help us solve many of the world's problems. However, no one really knows what will happen if machines become more intelligent than humans. They may help us, ignore us or destroy us. I tend to believe AI will have a positive influence on our future lives, but whether that is true will be partly up to us.

    Scientist B: I have to admit that the potential consequences of creating something that can match or go beyond human intelligence frighten me. Even now, scientists are teaching computers how to learn on their own. At some point in the near future, their intelligence may well take off and develop at an ever-increasing speed. Human beings evolve biologically very slowly and we would be quickly substituted. In the short term, there is the danger that robots will take over millions of human jobs, creating a large underclass of unemployed people. This could mean large-scale poverty and social unrest. In the long term machines might decide the world would be better without humans.

    Scientist C: I'm a member of the Campaign to Stop Killer Robots. Forget the movie image of a terrifying Terminator stamping on human skulls and think of what's happening right now: military machines like drones, gun turrets and sentry robots are already being used to kill with very little human input. The next step will be autonomous “murderbots” following orders but finally deciding who to kill on their own. It seems clear to me that this would be extremely dangerous for humans. We need to be very cautious indeed about what we ask machines to do.

    One of the problems with passwords (密码) is that users forget them. In an effort to remember them, people use simple things like their dog's names and their birth dates — anything that will give them a clue to remember what their passwords are. But for a hacker(黑客), this is the same as locking your door and leaving the key under the doormat(门口地垫).

    To create a safe password that is easy to remember, follow these simple steps:

    You should never use personal information as part of your password. It is very easy for someone to guess things like your last name and your pet's name.

    With the help of today's computing power, it doesn't take long to try every word in the dictionary and find your password, so you'd better not use real words for your password.

    You can make a password much safer by mixing different types of characters. Use some capital letters along with small letters, numbers and even special characters such as & and %.

    In order not to create a password using different character types that is hard to remember or using a word from the dictionary, you can use a "passphrase(代码)". Think of a sentence from a song or a poem that you like and create a password using the first letters from each word. For example, instead of just setting a password like "yr$1Hes", you can take a sentence such as "I like to read the about.com Internet network security website" and make it a password like "il2rta!nsw" by using the number "2" for the word "to" and using "!" in place of "Internet". You can use many characters types and create a safe password that is hard to guess, but much easier for you to remember.

The best books of the year

    One of the most famous buildings in the United States is Carnegie Hall, the home of classical and popular music concerts in New York. Carnegie Hall is known not just for its beauty and history, but also for its amazing sound. Carnegie Hall is named after Andrew Carnegie, who paid for its construction. Construction of Carnegie Hall began in 1890 and the official opening night was on May 5th, 1891.

    The hall was owned by the Carnegie family until 1924 when it was sold to Robert E Simon. The building became very old and in 1960, the new owner made plans to destroy it and build an office block. Isaac Stem led a group of people who fought to save Carnegie Hall and finally, the city of New York bought it for $5 million. It was then fixed up between 1983 and 1995.

    Advertisements and stories in newspapers about how Carnegie Hall needed help to recover its history led people to send in old concert programmes and information from all over the world. Over 12,000 concert programmes were received and with these it was possible to make a proper record of Carnegie Hall's concert history.

    Carnegie Hall is actually made up of several different halls, but the Main Hall, now called the Isaac Stem Auditorium, is the most famous. The hall itself can hold an audience of 2,804 in five levels of seating.

    Because the best and most famous musicians of all time have played at Carnegie Hall, it is the dream of most musicians who want to be great to play there. This has led to a very old joke which is now part of Carnegie Hall's history. Question: “How do I get to Carnegie Hall?” Answer: “Practice, practice, practice.”