If you're a high school student，you may tend to measure your self－worth based on your popularity and status.You may feel dejected or disappointed if you have a difficult time fitting in or if you lack the confidence to talk to others.If you want others to like you，you'll need to have a healthy understanding of how people think，what appeals to them and how you can gain their approval.There are four tips on how to be popular in high school.And if you are popular with your classmates，you can get many benefits from it.

    You must be yourself in order to gain any real popularity in high school.While imitation is the sincerest form of flattery(奉承)，copying another's style and personality will have a negative effect on your popularity.If you're not comfortable enough to be yourself 100 percent of the time，others won't feel comfortable around you.If you establish your own style and finesse and stay true to yourself，popularity will soon follow.

    Make yourself approachable to appeal to others and be popular in high school.People love to be around others who are confident and ready to have a good time.Hold your head up high，keep your shoulders back，and smile as you walk with an air of confidence to instantly attract others and boost your popularity.

    Be friendly and kind to everyone you meet.It's not enough to gain the approval of the other popular students in your school.In order to gain real popularity，you'll need to be kind and polite to everyone you meet.Make an effort to talk to your classmates regardless of their popularity or economic status and try to develop friendships with them.The more people you appeal to，the more popular you'll become.

    Involve yourself in school activities that interest you.You can be popular in high school if you play an active role in your school's extracurricular activities(课外活动)．The more you participate in group activities，the more popular you'll become.

    How Did the Ancient Chinese Keep Food Warm in Winter?

    Facilities like electric rice cookers, microwaves, and electric kettles, make it easy for people to keep food warm and enjoy a comfortable winter. So how did Chinese people in ancient times keep food warm in winter without these? In fact, ancient Chinese people used their own methods of heat preservation as early as the Shang and Zhou Dynasties.

    ☆ “Wen Ding”, ancient rice cooker

    One of the major functions of an electric rice cooker is to keep food warm. The “Wen Ding”, an ancient cooking container, served the same purpose, but instead of using electric energy, the ancient cooking container preserved heat by burning fuels like charcoal.

    The “Wen Ding” unearthed in Nanjing in 1989 is thought to be the oldest of its kind discovered in China, dating back to the Stone Age. The craftsmanship of making the “Wen Ding” was developed in the Bronze Age. The bronze Ding from the Shang and Zhou Dynasties took on different shapes and structures.

    ☆ “Ran Lu”, ancient small hot pot

    The “Ran Lu” is a small size cooking vessel (器皿) made of bronze, which can be divided into three parts. A charcoal stove forms the main structure, with a bottom tray to hold charcoal ashes, and a movable cup at the top. Some experts have concluded that the vessel's structure suggests it may have been used as a small hot pot and that these vessels became popular in the Warring States Period (475—221 B.C.).

    ☆ Bronze You, ancient kettle

    The Bronze You was one of the most common wine containers during the Shang and Zhou Dynasties. The Bronze You can also be used to warm wine. For example, the Bronze You with beast mask design, unearthed in Jiangxi Province, has an opening where charcoal could be placed. Just as people today can't do without an electric kettle, the Bronze You allowed people to enjoy a hot drink.

    ☆ Bronze Yan, ancient steamer

    Although the “Wen Ding” was effective at keeping food warm, the ancient Chinese people later found that its burning process produced pollution. As a result, the Bronze Yan made with a two-tier structure and used to steam rice and other grains. After the Eastern Han Dynasty (25A.D.-220A.D.), further improvements to the Bronze Yan led to the modern-day steamer.

    “I could see a huge flow (流动) of water, coming down fast from very high. I had no idea of shape, or situation, or anything. It was just so big.”

    These are the words of the great English writer Charles Dickens. He wrote them when he was visiting Niagara Falls. This waterfall is on the border (边界) of the United States and Canada. It is one of the largest in the world, and the largest in North America.

    Niagara Falls is on the Niagara River. The river divides just before the waterfall, and there are actually three waterfalls. On the American side are American Falls and Bridal Veil Falls. Horseshoe Falls is mostly on the Canadian side. The name comes from its shape — like a horseshoe, in a half circle. Horseshoe Falls is the widest of the three.

    People mainly know about Niagara Falls because of its size and natural beauty. However, the Niagara River is also an important source of electricity.

    In the 1890s, the Westinghouse Electric Company built a large power system (电力系统) on the river. Many other companies also hoped to use the land around Niagara Falls for factories and power systems. However, around the same time, many people began to work to protect the natural area. Soon, the governments of the United States and Canada got involved with it. They protected the land around Niagara Falls. They made parks — green, natural areas. No one could buy this land for factories. For hundreds of years, millions of people have visited Niagara Falls to enjoy its beauty.

    From the first use of the rocket to carry satellites into space to the setting up of space stations, human beings have been putting great effort into space research. And so far, we have achieved many successes. But there are still numerous tasks in front of us and we should not stop trying to progress.

    The international space station （ISS） is an important step we should take in space exploration. It is not only helpful but also essential. It provides a proper space environment for many experiments that we have wanted to do for a long time. It is also a base for the observations of the earth and the universe. It could also be an important base for later travel to the moon and Mars. In a word, if we want to explore space more, the first thing we should do is to set up a space station.

    As the space station costs a lot of money, it is hard for one country alone to establish one. The USA seem to be the only country that has the ability to build a space station alone, and it has tried to do so, but not very successful. So it aggregated many other countries to work on it together. Though it is still extremely expensive, it is much cheaper than doing it alone. It is really a job that needs everyone's effort and will benefit everyone.

    Led by the U. S. and Russia, the ISS is a joint project between six space agencies involving 16countries. Called the greatest achievement in human cooperation, the ISS has come to the end of a ten﹣year's hard work in construction. China has applied for participation in （taking part in） the project many times. Unfortunately all the applications were rejected, which drove China onto the path of independent development. As the Long March Ⅱ﹣F/T1 carrier rocket blasted off （leave the ground） and successfully carried the Tiangong﹣1into space on September 29, 2011, China takes a big step toward its Space Station Era.

    Some West media suggested that the successful launch of Tiangong﹣1 would disturb the balance of global space power, raising concerns about "China threat". China's space project is not designed for military purpose but for developing space technology to explore space resources and make use of them for mankind's well﹣being.

    Every morning, Ben Mumford starts his school day with math. At the age of ten, he is already working at GCSE level, but he does not always bother to get out of his pajamas (睡衣裤) in time for the class. He reads more books than most of his friends, studies science on the beach, and recently built a go-kart (卡丁车) in a technology lesson. Ben is happy and fulfilled, all, his mother believes, thanks to homeschooling.

    Homeschooling is not what it used to be. What emerged in the 1970s as a way for Catholic (信天主教的) parents to infuse (灌输) religion into their kids' education is now probably the fastest-growing form of education in the U.K. The number of homeschooled children has risen by about 40 percent over three years. Here are a handful of reasons why homeschooling makes sense in the 21^st century.

    Contrary to the name, homeschooling takes place in an actual home only a small part of time. A great deal of instruction happens in libraries, museums and community colleges. These experiences have the effect of helping kids mature much more quickly and developing a trait of open-mindedness.

    The key idea of homeschooling is that kids need to learn at the speed, and in the style, most appropriate for them. Without formal curriculum to guide their education, homeschoolers get the chance to explore a range of topics that might not be normally offered until high school or college. They can study psychology in the fourth grade, or finance in the eighth grade.

    The most common misunderstanding about homeschoolers is that they lack social skills. However, social media makes it convenient for homeschoolers of today to have just as much opportunity to make friends as kids studying in traditional schools. Meanwhile, they do not need to deal with the potential problems of being around kids in a school environment, including bullying, which might result in anxiety and depression.

    For most people, school is really good, and it works for them because they learn in the way that school teaches. However, there are so many different ways of learning and processing (处理) information and knowledge. It does not necessarily work for everyone.

Steager is an engineer at the University of Pennsylvania. His colleague Hyun Koo is an inventor and dental researcher there. Together, they found a way to form the nanoparticles（纳米颗粒）into long, skinny bristles（鬃毛）, a lot like the ones on a toothbrush. But these bristles shape-shift to fit whatever surface they encounter. They can even squeeze between teeth.

"A new way to clean teeth could help out anyone who finds this chore boring," says Koo. But it would be especially life-changing for people with disabilities or illnesses that make it difficult or impossible to hold and move a toothbrush.

The tooth-cleaning robot works thanks to two magnets（磁铁）. One goes on each side of the teeth. The nanoparticles sit in a water-based solution between the magnets. When the magnets are turned off, the nanoparticles float randomly in the solution. As soon as one magnet gets turned on, the nanoparticles clump together near its center. When you turn on the other magnet and turn off the first one, the nanoparticles extend outward in long, skinny bristles.

When there's a tooth in the way, these bristles can't stretch out as far as they want. So they push against the tooth's surface. If there's a gap between teeth, they push into the gap. Moving the magnets makes the bristles move against and between teeth.

Besides, as a bonus, the nanoparticles can kill what harms the teeth and keep them health y because it contains something commonly added to toothpaste and mouthwash.

The new invention is just a proof of concept. The researchers still need to turn it into a product that people will want to use. It must fit comfortably and safely in people's mouths. It can't draw too much power or cost too much. "There's a lot of engineering to get from here to there," says Steager. But he adds, "every good idea needs to have a start."