Every animal sleeps,but the reason for this has remained foggy. When lab rats are not allowed to sleep, they die within a month.{#blank#}1{#/blank#} 

    One idea is that sleep helps us strengthen new memories. {#blank#}2{#/blank#} We  know that, while awake,fresh memories are recorded by reinforcing (加强)connections between brain cells, but the  memory processes that take place while we sleep  have been unclear.

    Support is growing for a theory that sleep evolved so that connections between neurons(神经元)in the brain can be weakened overnight, making room for fresh memories to form the next day.  {#blank#}3{#/blank#}

    Now we have the most direct evidence yet that he is right. {#blank#}4{#/blank#} The synapses in the mice taken at the end of a period of sleep were 18 per cent smaller than those taken before sleep,showing that the connections between neurons weaken while sleeping.

If Tononi's theory is right, it would explain why, when we miss a night's, we find it harder the next day to concentrate and learn new information —our brains may have smaller room for new experiences.

    Their research also suggests how we may build lasting memories over time even though the synapscs become thinner. The team discovered that some synapses seem to be protected and stayed the same size. {#blank#}5{#/blank#}  “You keep what matters,” Tononi says.

    My name is Clara. I still remember that chilly December day,sitting in science class. I'd finished a worksheet early and picked up a TIME for Kids magazine. A piece of news caught my eye: NASA was holding an essay contest to name its Mars rover(火星探测器). Before I even knew anything else about it,a single word flooded my 11-year-old mind, Curiosity.

    I couldn't want for the bell to ring so I could get started on my essay.That afternoon, I raced home, sat down at the computer, and typed until my fingers ached. “Curiosity is an everlasting flame that burns in everyone's mind...”

    Five months later, my mon received a phone call, and immediately, a wide smile spread across her face.

    On August 5,2012, at 10:31 p.m, the rover named Curiosity touched down safely on the surface of Mars,and I was honored to have a front-row seat in NASA.

    Curiosity is such an important part of who I am.I have always been fascinated by the stars,the planets,the sky and the universe. I remember as a little girl,my grandmother and I would sit together in the backyard for hours.She'd tell me stories and point out the stars,Grandma lived in China,thousands of miles away from my home in Kansas,but the stars kept us together even when we were apart.They were always there, yet there was so much I didn't know about them.That's what I love so much about space.

    People often ask me why we go to faraway places like Mares.My answer is simple because we're curious.We human beings do not just hole up in one place.We are constantly wondering and trying to find out what's over the hill and beyond the horizon.

How to become a professional athlete?

    Everyone wants to be a superstar athlete. However, there is a lot of competition to make it. So if you want to be a professional athlete, you have to know all the tricks of the trade to rise up above the rest.

{#blank#}1{#/blank#}

    To play your sport better than anyone else, you have to practice your skills with lots of repetition. For example, you have to shoot 100 free throws every day for basketball.

    Make steady improvements

    If you are a baseball pitcher (投手) and your fastball is stuck at about 60 miles per hour, change it up! Try to walk your first step a little bit longer, bring in your elbow a little bit tighter, or try to reach higher when you're following through{#blank#}2{#/blank#}

Quality coaches

    Have you ever noticed that a lot of kids with parents who are professional athletes will often become professional athletes in the same sport? They have access to a professional athlete's tips and tricks{#blank#}3{#/blank#} You should try to find coaches or professional athletes that are willing to answer your questions.

Diet of champions

    {#blank#}4{#/blank#} If you can change your diet to a healthy one, you're going to be stronger.

    Friends and enemies

    {#blank#}5{#/blank#} By having great teammates or competitors, it pushes you to try harder and that always results in getting better.

A. Practice makes perfect

B. Better late than never

C. The big secret to advancing your skills above anyone else is to improve.

D.The biggest thing that most kids often ignore is their diet.

E.Surrounding yourself with quality teammates and competitors is the best way to get better.

F. These little improvements are things that will help you advance your skills.

G.But don't get discouraged if you don't have parents who were professional athletes.

    The new school year is right around the corner, and the adjustment to returning to school may take a few weeks.{#blank#}1{#/blank#} Kids today are faced with far more than learning new material. Interacting with teachers and other students, bullying (欺凌), peer pressure and school violence are just a few of the challenges children face. The Kern County Sheriff s Office would like to provide the following tips for parents on how to protect your children, and how to teach them to protect themselves.

    {#blank#}2{#/blank#}

    Map out a safe way for your children to walk to school or to the bus stop. Teach your children to always be aware of their surroundings. {#blank#}3{#/blank#} Choose a different route or walk on the opposite side of the street.

    Bus Safety

    Make sure your children arrive at least five minutes early for the bus. Be aware that bullying often happens on the bus. Ask your children about their bus rides, who they sit with, and what goes on in the bus.{#blank#}4{#/blank#}

    After School

    {#blank#}5{#/blank#} It could be your parents or any of your neighbors who can take care of your children for you. Make sure they inform you of it the moment your children arrive home.

    At School

    Teach your children to resolve problems without fighting. Many parents mislead their children to solve problems by force in fear that their children may be bullied at school, which will only lead to more trouble. Anyway, encourage your children to report bullying behavior, either as a victim or a witness.

A. Getting to School

B. Preparing for School

C. Encourage them to report any bullying behavior on the bus.

D. Some kids just can't wait to return to school after a long holiday.

E. Have your children check in with an adult as soon as they get home.

F. Be aware of slow moving vehicles or parked vehicles that appear to be occupied.

G. Returning to school can be fun and exciting, but it can also be difficult for some children.

    Most people have a list of wishes—things that they think will bring them happiness. Happiness lists are easy to come up with. However, the mechanism behind them is somewhat complicated, since it involves what psychologist Daniel Gilbert calls the greatest achievement of the human brain—the ability to imagine. To imagine what will bring joy to our future selves requires mental time travel, which is a unique human skill resulting from two million years of evolution. We use this skill every day, predicting our future emotions and then making decisions, whether big or small, according to our forecasts of how they'll make our future selves feel.

    Yet, our imagination often fails us. When we're lucky enough to get what we wished for, we discover that it doesn't come with everlasting happiness. And when the things we feared come to pass, we realize that they don't crush us after all. In dozens of studies, Gilbert has shown that we can mispredict emotional consequences of positive events, such as receiving gifts or winning football games, as much as negative events, like breaking up or losing an election. This impact bias(影响偏差) —overestimation of the intensity and duration of our emotional reactions to future events—is significant, because the prediction of the duration of our future emotions is what often shapes our decisions, including those concerning our happiness.

    Just as our immune systems work tirelessly to keep our bodies in good health, our psychological immune systems routinely employ an entire set of cognitive(认知) mechanisms in order to deal with life's habitual attack of less-than-pleasant circumstances. Actually, our psychological immune system has an impressive feature of its own: the ability to produce happiness. Thus, when life disappoints us, we "ignore, transform, and rearrange" information through a variety of creative strategies until the rough edges of negative effects have been dutifully dulled. When we fail to recognize this ability of our psychological immune systems to produce happiness, we're likely to make errors in our affective forecasting.

    Happiness, Gilbert points out, is a fast moving target. As passionate as we're about finding it, we routinely misforecast what will make us happy, and how long our joy will last. In reality, he adds that the best way to make an affective forecast is not to use your imagination, but your eyes. Namely, instead of trying to predict how happy you 'll be in a particular future, look closely at those who are already in the future that you're merely contemplating(冥想)and ask how happy they are. If something makes others happy, it'll likely make you happy as well.

    The environmental group Heal the Bay organized a beach clean-up. And I was one of the volunteers. We went to Venice Beach to clean up the trash.

    At first glance, the beach didn't look dirty at all. But then I saw a Styrofoam(泡沫)cup half buried in the sand on the beach. I pulled hard and finally got it out. As we moved farther, we found pieces of Styrofoam spread all over the sand. The Heal the Bay representative had told us that these little pieces of Styrofoam and other small pieces of plastic are what actually harm sea life most. Sea animals eat the plastic. After eating it, they think they are full. As a result, they can die of starvation as they are cheated by their feeling and don't think they need to eat any food.

    We kept on picking up the trash. Then I saw someone with a full Heal the Bay trash bag and I went to see what was inside. When I opened the trash bag, I found everything from a pair of old jeans and a brown belt to headphones and some plastic bags. It made me very angry with the people who left their things behind without thinking what effects they might have on the ocean.

    It is really important to protect the ocean. The ocean covers 70 percent of the Earth's surface. A clean ocean not only helps animals in the ocean survive but also helps us survive.

    By noon, the sun was shining and the temperature was rising. The volunteers that had spread out across Venice Beach were coming back to throw the trash they had collected into the truck. I could not believe how much trash there was. All together we collected more than 135 bags of trash. I do hope that next time people go to the beach, they will stop littering.