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.

    High school plays a major role in shaping up your future and your whole development. Extracurricular (课外的) activities along with the studies can be very helpful. Make yourself take part in various activities and at the same time try to stand out in your studies. When you move out to college these efforts that you put in may count for a lot.

    High school is not just about books or classes. Schools always provide opportunities for students to socialize (社交). There are various group tasks designed which allow the students to learn to work together.

    High school is the right time for you to discover yourself and bring out some of your hidden talents. In your lessons, you may find that you are better at English than you were earlier or have grown an interest for Math. High school also provides many other opportunities for students to take part in. These help develop leadership skills and management skills at an early age, which in turn is a way of preparing students to manage and plan their careers (事业) better.

    Balancing all activities is an experience in time management. If you have taken up a part-time job along with your high school you would have to arrange your time for studies, and extracurricular activities. Such management can go a long way in teaching you to manage things better when you take up a job. Moreover, they help build your character. You would be better prepared for additional stress that you may feel sometimes.

    When at high school you should pick up your classes wisely. Depending upon what you like and your career plan you should choose suitable classes. Doing something that you hardly like may get you very low grades as well as lose valuable time. Take up interesting and challenging classes that would allow you to put in those extra efforts.

    When I began planning to move to Auckland to study, my mother was a little worried about the uncertainty of living in a place that was so different from India, where we lived. She worried particularly about the lack of jobs, the cultural differences and the chance that I would face racism(种族偏见).

    Despite these worries, I came to New Zealand in July 2009. I have found the place and people very nice and supportive. Soon after I arrived, I realized the importance of getting a job for my living expenses.

    Determined to do this on my own, I spent a whole day going door to door asking for a job. However, I received little response. This became my routine every day after college for a few weeks.

    One afternoon, I walked into a building to ask whether there were any job opportunities. People there were very surprised, and advised me not to continue my job search in that manner. As I was about to leave, a clerk in the building, who had been listening to what the others had said, approached me and asked me to wait outside for a while. Fifteen minutes later, he returned. He asked me about my plans and encouraged me to stay confident. Then he offered to take me to Royal Oak to search for a job.

    I was a little surprised but had a good feeling about him. He gave me some suggestions on dressing and speaking. I handed out my resumes and went home feeling very satisfied. The following day, I received a call from a store in Royal Oak offering me a job.

    It seems that the world always gives back to you when you need it .And this time，it was a complete stranger who turned out to be a real blessing.

    New York City is a world capital in every sense of the word—it's a cultural and economic powerhouse, and arguably the most influential city on the planet. But it wasn't always this way, as the following cities once dominated the world around them.

    Djenne­Djenno

    In the flood lands of the Niger delta people have been building houses and other structures with clay for centuries. The town of Djenne­Djenno is made entirely out of clay. It was inhabited as far back as 250 BC, and became an important link in the trans­Saharan gold trade(跨撒哈拉黄金交易). Constructed on hills called " toguere", the city managed to escape the marshy(沼泽 ) landscape and annual floods produced by the rainy season. Djenne­Djenno is believed to be one of the earliest settlements in the sub­Saharan region, and is considered by some to be "the typical African City".

    Archeological evidence shows us a continuous human presence in the area up until the 14th century AD, when people moved to the nearby town of Djenne, founded in the 11th century. Further evidence points out that even before the city's construction, the Bozo people were growing wild rice in the region. In the 13th century AD, with King Koumboro's conversion to Islam, its palace transformed into a mosque.

    Carthage

    Legend has it that Carthage was founded by Queen Dido of the Phoenicians. She fled the city of Tyre located in present­day Lebanon in order to escape the hatred of her brother Pygmalion, who was her rival to the throne. Along with a group of settlers, she traveled a great distance by sea and landed in North Africa, where she met King Iarbas. He offered to give them land in order to build a settlement, but no bigger than the surface covered by the hide(牛皮) of an ox. They cleverly cut the hide into thin strips and were able to enclose a fairly large area of land. On this land, the mighty city of Carthage was built.

    These stories are most likely just that, but the fact that the Phoenicians built the city around 760 BC is true. Located in such a good position—in the middle of the Mediterranean, close to Sicily, Sardinia and Corsica, and a pretty good distance from Egypt—helped make Carthage a leading trade center and military power. The population soon reached half a million citizens and, in order to house them all, buildings were all built five or six stories tall. Carthage was the first city in ancient times to have a centralized sewage system, linking all buildings within the city walls. The most notable of structures among the ruins was the " Thophet", which is believed to be an altar(圣坛) for child sacrifice.

    Tenochtitlan

    Tenochtitlan was the capital city of the Aztec Empire. It was built on an island surrounded by Lake Texcoco deep inside the jungles of Central America. By the time the Spanish conquerors were aware of its existence, the population was around 200，000. This was a city very different from what the Europeans were used to. Founded in 1325 AD, the Aztec capital was joined to the mainland by three causeways(堤道). It was laid out in straight street grids and had enormous pyramids at its center, which were surrounded by the skulls of the dead and ceremonial sculptures.

    A telescope, called Gaia, is being designed by astronomers in Europe, and it couldn't be more different from Pan-STARRS, which is another telescope being designed. While Pan-STARRS will be looking for asteroids (小行星) and comets headed for Earth, Gaia will be looking at our entire galaxy (银河系).

    Gaia is designed to draw a map of the Milky Way, our home galaxy. Just as a map of your town gives you a picture of where things are located, Gaia's map of the galaxy will tell astronomers where the stars are. Over five years, Gaia will observe (观察) about a billion stars and other objects in our galaxy. Each object will be observed about 70 times.

    Gaia will be sent into space connected to a rocket. It contains two telescopes, each focused at a different angle (角度). These two telescopes act like Gaia's “eyes”. The reason why humans can see things in 3D is that we have two eyes focused on the same object, at slightly different angles. By using two telescopes like eyes, Gaia can produce the first 3D map of the positions of the stars it views.

    Gaia, which is to be sent into space, will be a powerful telescope. If you were to use it on Earth, for example, you could stand 600 miles away from your best friends and still get a clear picture of their hair.

    Gaia is one of more than a dozen telescopes being designed by scientists right now. The next generation of telescopes will reveal new parts of our universe that will seem surprising. The universe, with all its planets, stars and other strange objects, is a puzzle with pieces that we can see by using powerful telescopes.

Babies made from three people approved in UK

    Babies made from two women and one man have been approved by the UK's fertility regulator. The historic and controversial move is to prevent children from being born with deadly genetic diseases.

    Doctors in Newcastle — who developed the advanced form of In Vitro Fertilization or IVF (人工授精) — are expected to be the first to offer the procedure and have already appealed for donor eggs. The first such child could be born, at the earliest, by the end of 2017.

    Some families have lost multiple children to incurable mitochondrial (线粒体的) diseases, which can leave people with insufficient energy to keep their heart beating.

    The diseases are passed down from only the mother, so a technique using a donor egg as well as the mother's egg and father's sperm has been developed.

    The resulting child has a tiny amount of their DNA from the donor, but the procedure is legal and reviews say it is ethical (伦理的) and scientifically ready.

    "It is a decision of historic importance," said Sally Cheshire, chairwoman of the Human Fertilisation and Embryology Authority (HFEA). "I'm sure patients will be really pleased by what we've decided today."

    But some scientists have questioned the ethics of the technique, saying it could open the door to genetically-modified(转基因) 'designer' babies.

    The HFEA must approve every clinic and every patient before the procedure can take place. Three-person babies have been allowed only in cases where the risk of a child developing mitochondrial disease is very high.

    Prof Mary Herbert, from the Newcastle Fertility Centre, said, "It is enormously pleasing that our many years of research in this area can finally be applied to help families affected by these devastating diseases".

    "Now that we are moving forward towards clinical treatments, we will also need donors to donate eggs for use in treatment to prevent affected women transmitting disease to their children."

    Prof Sir Doug Turnbull, the director of the Welcome Centre for Mitochondrial Research at Newcastle University, said, "We are delighted by today's decision. We will also provide long-term follow up of any children born."

    NHS England has agreed to fund the treatment costs of the first trial of three-person IVF for those women who meet the HFEA criteria, as long as they agree to long-term follow up of their children after they are born.