Space is where our future is — trips to the Moon, Mars and beyond. Most people would think that aside from comets(彗星) and stars, there is little else out there. But, since our space journey started we have left so much trash(垃圾) there that scientists are now concerned that if we don't clean it up, we may all be in mortal(致命的) danger.

    The first piece of space junk was created in 1964, when the American satellite Vanguard Ⅰ stopped operating and lost its connection with the ground center. However, since it kept orbiting around the Earth without any consequences, scientists became increasingly comfortable abandoning(抛弃) things that no longer served any useful purpose in space.

    It is estimated(估计) that there are now over 500,000 pieces of man-made trash orbiting the Earth at speeds of up to 17,500 miles per hour. The junk varies from tiny pieces of paint chipped off rockets to cameras, huge fuel tanks, and even odd items like the million-dollar tool kit that astronaut Heidemarie Stefanyshyn Piper lost during a spacewalk.

    The major problem with the space trash is that it may hit working satellites and damage traveling spacecraft(飞船). Moreover, pieces of junk may collide(碰撞) with each other and break into pieces which fall back to the Earth. To avoid this, scientists have invented several ways for clearing the sky. Ground stations have been built to monitor larger pieces of space trash to prevent them from crashing into working satellites or space shuttles. Future plans include a cooperative effort among many nations to stop littering in space and to clean up the trash already there.

    Cheating can happen in a lot of different ways. When people cheat, it's not fair to other people, like the kids who studied for the test or who were the true winners of a game.

Many people like the action of cheating. It makes difficult things seem easy, like getting all the right answers on the test. But it doesn't solve the problem of not knowing the material and it won't help on the next test — unless the person cheats again.

    Some people lose respect for cheaters and think less of them. The cheaters themselves may feel bad because they know they are not really earning that good grade. And, if they get caught cheating, they will be in trouble at school, and maybe at home, too.

    Some kids cheat because they're busy or lazy and they want to get good grades without spending the time studying. Other kids might feel like they can't pass the test without cheating. Even when there seems to be a “good reason” for cheating, cheating isn't a good idea.

    If you were sick or upset about something the night before and couldn't study, it would be better to talk with the teacher about this. And if you don't have enough time to study for a test because of swim practice, you need to talk with your parents about how to balance swimming and school.

    A kid who thinks cheating is the only way to pass a test needs to talk with the teacher and his or her parents so they can find some solutions together. Talking about these problems and working them out will feel better than cheating.

                                        Do dogs understand us?

    Be careful what you say around your dog. It might understand more than you think.

    A border collie named Rico recognizes the names of about 200 objects, say researchers in Germany. The dog also appears to be able to learn new words as easily as a 3-year-old child. Its word-learning skills are as good as those of a parrot or chimpanzee(黑猩猩).

    In one experiment, the researchers took all 200 items that Rico is supposed to know and divided them into 20 groups of 10 objects. Then the owner told the dog to go and fetch one of the items and bring it back. In four tests, Rico got 37 out of 40 commands right. As the dog couldn't see anyone to get clues, the scientists believe Rico must understand the meanings of certain words.

    In another experiment, the scientists took one toy that Rico had never seen before and put it in a room with seven toys whose names the dog already knew. The owner then told Rico to fetch the object, using a word the dog had never heard before.

    The correct object was chosen in seven out of l0 tests, suggesting that the dog had worked out the answer by process of elimination(排除法). A month later, Rico remembered half of the new names, which is even more impressive.

    Rico is thought to be smarter than the average dog. For one thing, Rico is a border collie, a breed (品种)known for its mental abilities. In addition, the 9-year-old dog has been trained to fetch toys by their names since the age of nine months.

    It's hard to know if all dogs understand at least some of the words we say. Even if they do, they can't talk back. Still, it wouldn't hurt to sweet-talk your dog every now and then. You might just get a big, wet kiss in return!

    I was in a terrible mood. Two of my friends had gone to the movies the night before and hadn't invited me. I was in my room thinking of ways to make them sorry when my father came in.

    "Want to go for a ride, today, Beck? It's a beautiful day."

    "No! Leave me alone!" Those were the last words I said to him that morning. My friends called and invited me to go to the mall with them a few hours later. I forgot to be mad at them and when I came home to find a note on the table. My mother put it where I would be sure to see it.

    "Dad has had an accident. Please meet us at Highland Park Hospital".

    When I reached the hospital, my mother came out and told me my father's injuries were extensive. "Your father told the driver to leave him alone and just call 911, thank God! If he had moved Daddy, there's no telling what might have happened. A broken rib（肋骨）might have pierced（穿透）a lung..."

    My mother may have said more, but I didn't hear. I didn't hear anything except those terrible words: Leave me alone. My dad said them to save himself from being hurt more. How much had I hurt him when I hurled those words at him earlier in the day?

    It was several days later that he was finally able to have a conversation. I held his hand gently, afraid of hurting him.

    "Daddy… I am so sorry…"

    "It's okay, sweetheart. I'll be okay. "

    "No," I said, "I mean about what I said to you that day. You know, that morning?"

My father could no more tell a lie than he could fly. He looked at me and said. "Sweetheart, I don't remember anything about that day, not before, during or after the accident. But I remember kissing you goodnight the night before. "He managed a weak smile.

    My English teacher once told me that words have immeasurable power. They can hurt or they can heal. And we all have the power to choose our words. I intend to do that very carefully from now on.

    The secret to living longer could be as simple as picking up your walking pace, according to a new study. Researchers from the University of Sydney found that walking at a brisk (快的) or fast pace was associated with a risk reduction of 24 percent for any cause of death.

    This effect was even more obvious in older age group, with fast walkers over the age of 60 reducing their risk of death by a surprising 53 percent. Professor Emmanuel Stamatakis, who led the study, explained, "A fast pace is generally five to six kilometers per hour, but it really depends on a walker's fitness levels; an alternatives indicator is to walk at a pace that makes you slightly out of breath or sweaty."

    In the study, the researchers looked at the results of 11 surveys from 1994 to 2008, in which participants recorded their walking pace, as well as age, sex and BMI. The analysis showed that walking at an average pace was associated with a 20 percent risk reduction for all-cause mortality (死亡率) compared with walking at a slow pace, while walking at a brisk or fast pace was associated with a risk reduction of 24 percent.

    The researchers hope the findings will encourage the development of public health message about the benefits of walking pace. Professor Stamatakis added, "These analyses suggest that increasing walking pace may be a straightforward way for people to improve heart health and risk for premature mortality—providing a simple message for public health campaigns to promote.

    "Especially in situations when walking more isn't possible due to time pressures or a less walking-friendly environment, walking faster may be a good option to get the heart rate up—one that most people can easily add to their lives."

    A fresh and gentle wind on your face, soft sand under your feet and blue waters as far as the eye can see. Is there any other Olympic sport that is played in such pleasant conditions as beach volleyball?

    "I've gone to a lot of beautiful places, and met a lot of beautiful people. That wouldn't have happened if I had been playing another sport," said Randy Stoklos, America's most famous beach volleyball player.

    The sport began as a four-a-side game on beaches in Southern California in the 1920s.The first recorded two-man game took place there in 1930, and the first tournament was held in Los Angeles 18 years later. The winners were awarded a case of Pepsi. In the 1950s, women started playing and the sport soon spread to Europe and South America. Yet at that time, beach volleyball was more an entertainment show than a sport, with beauty contests included. The Association of Volleyball Professionals was founded in 1983 and beach volleyball developed into a fast, athletic sport. Its world-wide popularity won beach volleyball a place at the 1996 Olympics in Atalanta, where 24 male teams and 16 female teams took part. At present, the US and Brazil are the best in the world at beach volleyball.

    The game came to China in the early 1990s and there have been national tournaments since 1994. It became an official event at the Eighth National Games in 1997.China's You Wenhui and Wang Lu finished ninth in the women's beach volleyball world championships in Brazil.