We've talked about snails（蜗牛）and their slow move.But much of the time snails don't move at all.They're in their shells（壳）—sleeping.

    Hot sun will dry out a snail's body.So at the least sign of hot sun,a snail draws its body into its shell and closes the opening with a thin cover.Then it goes to sleep.A snail will die in a heavy rain.So whenever it rains,it goes inside its shell house and goes to sleep.A snail can sleep for as long as it needs to.It can take a short sleep.Or it can sleep for days at a time.And it spends all the winter months in its shell,asleep.

    the shell.When hungry,the snail looks for food.It can't see very well.Its eyes,at the ends of the top feelers（触角）are very weak.But its sense of smell is very strong.It helps the snail to the new greens.Then the snail's little mouth goes to work.

    A snail's mouth is no longer than the point of a pin（针）.Yet it has 256,000 teeth!The teeth are so small that you can't see them.But they do their work.If you put a snail in a hard paper box,it will eat its way out.And if a snail wears out its teeth,it will grow new ones.

    Mostly,a snail looks for food at night.But on cloudy days it eats in the day time.It cats all day long.A snail can go on eating for hours and never feel full.

    Food is one of the necessities in our daily life. It serves as a form of communication in two fundamental ways. Sharing bread or other foods is a common human tradition that can promote unity and trust. Food can also have a specific meaning, and play a significant role in a family or culture's celebrations or traditions. The foods we eat—and when and how we eat them—are often unique to a particular culture or may even differ between countrysides and cities within one country.

    Sharing bread, whether during a special occasion or at the family dinner table, is a common symbol of togetherness. Many cultures also celebrate birthdays and marriages with cakes that are cut and shared among the guests. Early forms of cake were simply a kind of bread, so this tradition hits its roots in the custom of sharing bread.

    Food also plays an important role in many New Year celebrations. In the southern United States, pieces of corn bread represent blocks of gold for prosperity (兴旺) in the New Year. In Greece, people share a special cake called vasilopita. A coin is put into the cake, which signifies (预示) success in the New Year for the person who receives it.

    Many cultures have ceremonies to celebrate the birth of a child, and food can play a significant role. In China, when a baby is one month old, families name and welcome their child in a celebration that includes giving red-colored eggs to guests. In many cultures, round foods such as grapes, bread, and moon cakes are eaten at welcome celebrations to represent family unity.

    Nutrition is necessary for life, so it is not surprising that food is such an important part of different cultures around the world.

    Camp All-Star

    One of a Kind Summer Camps for Kids

    Welcome to Camp All-Star, your No. 1 summer sports camp for kids! Located on the famous Kents Hill School campus by the beautiful lake, Camp All-Star hosts kids from around the world. When thinking about your next overnight summer camp, consider the best—Camp All-Star!

    Great Sports Summer Camps for Kids

    Camp All-Star stands out among the successful camps in the U.S. We have the best sports fields and courts to make your child's sports camp experience a successful one. Your child can enjoy playing for hours in any of our more than 30 sports and activities each day. Our camper to staff rate is three to one, which makes it possible for children to receive more careful instruction.

    We have a wide variety of activities and sports to choose from: fishing, dance, basketball, soccer, baseball, and tennis. Boys and girls, aged 8-16, can customize their own schedules in our 2, 3, 4 or 6 week summer camp session for kids.

    The aim of Camp All-Star is to develop athletic skills, encourage abilities in leadership, fair play and team work, and provide a fun, rewarding and memorable summer sports camp experience. Our staff have the experience and qualified training necessary to ensure that your child has a successful, memorable and enjoyable time at our summer camp.

    Call Today About Our Overnight Summer Camps for Kids

    Don't let your kids waste another summer playing video games and sitting around. Let them enjoy their time and get some exercise at our exciting and friendly summer sports camp. Information for our upcoming camps can be found on our website. For additional information or questions, contact us today. We hope your kids can join us at Camp All-Star!

    We humans spend about one-third of our lives asleep. This may sound like a lot of time, but it is not wasted. Sleep not only helps us stay healthy but it also helps our brains remember. Our brains need good sleep to remember what we do and learn during the other two thirds of our lives when we are awake.

    Researchers at the University of Wisconsin-Madison have found that sleep helps improve brain performance by shrinking(收缩)synapses in the brain. A synapse is the area where cells pass messages to other cells.

    Scientist Chiara Cirelli is a leader at the school's Center for Sleep and Consciousness. She told the reporter that sleep is when the human brain mixes information it has learned while awake into its general collection of knowledge. Meanwhile, the brain forgets unimportant details. This forgetting is important. It makes space for new learning and new memories.

    Cirelli said that the Centers research began with this hypothesis(假设): We sleep so that our brain can repair and refresh itself. She said the idea seems simple and reasonable. However, testing and discovering how it works has been extremely difficult.

    Synapses are only about 20-40 nanometers(纳米)wide. The team began their study by measuring the size of the synapses to look for changes in these already tiny spaces between nerve cells. Cirelli says the process(过程) is difficult because"all the actual measurements of the synapses have to be done by hand." The team had to wait until improvements in laboratory technology made it possible to see these tiny changes. A University of Wisconsin press release called the research a"huge job." Many research specialists worked for four years to photograph, rebuild and study certain areas of a mouse brain. The report also said the scientists measured 6,920 synapses.

    Cirelli says they found that our synapses shrink as our brains clean themselves during sleep. We wake up refreshed and ready to fill those synapses with new information. The research findings are the result of years of hard work at the University of Wisconsin Madison. The researchers published their findings in the journal Science.

Parties and social gatherings no longer excite us the same way they once did. This is not due to a lack of desire to socialize, but the smartphone.

At parties, people focus more on their smartphones than on their drinks. According to a recent study from International Data Corporation，over half of all Americans have a smartphone and reach it the moment they wake up, keeping it in hand all day. In addition, too many people are using smartphones while driving and as a result, they get into car crashes. 34 percent of teens admit to text while driving, and they confirm that texting messages are the major interruption while driving. People's attachment (依恋) to their smartphones is unbelievably becoming more important than the lives of themselves and others.

Just as drivers dismiss the importance of focusing while on the road, many people also fail to recognize the significance of human interaction. When with their friends, some people pointlessly (无谓地) check or send messages in the presence of their friends., which means that their friends are less important. In addition, relying on our smartphones to make friends does not give us the same advantages as making new friends in the real world. Face-to-face conversations will give us the chance to improve our communication skills in the long run.

As many people risk their lives and the lives of people around them just to send a text or mindlessly check their messages, smartphones are in many ways more dangerous to people. The technology shows the achievement weaken the value of communication. Not only is the smartphone affecting our desire to interact face to face, but it is also lowering people's ability to communicate.

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."