Mark and his brother Jason both were looking at the shining new computer enviously. Jason was determined not to go against their father's wishes but Mark was more adventurous than his brother. He loves experimenting and his aim was to become a scientist like his father.

     “Dad will be really mad if he finds out you've been playing with his new computer” Jason said, “He told us not  to touch it.”

     “He won't find out,” Mark said, “I'll just have a quick look and shut it down.”

    Mark had been scolded before for touching his father's equipment. But his curiosity was difficult to control and this new computer really puzzled him.

It was a strange-looking machine — one his dad had brought home from the laboratory where he worked. “It's an experimental model,” his father had explained, so don't touch it under any circumstances.” But his father's warning only served to make Mark more curious. Without any further thought, Mark turned on the power switch. The computer burst into life and seconds later, the screen turned into colours, shifting and changing, and then two big white words appeared in the centre of the screen: “SPACE TRANSPORTER.”

     “Yes!” Mark cried excitedly, “It's a computer game. I knew it! Dad's only been pretending to work. He's really been playing games instead!” A new message appeared on the screen:

“ENTER NAMES

VOYAGE 1

VOYAGE 2

    Mark's finger flew across the keyboard as he typed in both of their names.

“INPUT ACCEPTED.

START TRANSPORT PROGRAM.

AUTO-RETRIEVE INITIATED( 自动回收程序已启动).”

    The screen turn even brighter and a noise suddenly rose in volume.

     “I think we'd better shut it off, Mark,” Jason yelled out in terror, reaching for the power switch. A beam(光束) of dazzling white light burst out of the computer screen, wrapping the boys in its glow(光芒)，until they themselves seemed to be glowing. Then it died down just as suddenly as it had burst into life. And the boys were no longer there. On the screen, the letters changed：

“TRANSPORT SUCCESSFUL．

DESTINATION:  MARS.

RETRIEVE DATE:  2025

    On a cool morning, Wilson Kasaine heads out along a dirt path in southern Kenya. His calmness makes it easy to forget that he's tracking one of the most dangerous animals in the world. Kasaine is tracking lions—especially one lion called Marti, who is the real-life Lion King of Selenkay Conservancy.

    Tracking lions on foot may sound like a death wish, but Kasaine has been doing it for most of his life. Born into a traditional Maasai family he quickly grew to understand the beauty and danger of wildlife. Living with big wild animals forces him to develop a good sense of where they have been and where they may be going. During his 12-kilometer walks to and from school, he learned how to tell the paw prints (爪印)of a lion from those of other animals.

    Growing up, Kasaine knew that improving his tracking abilities would help him avoid surprise meetings with dangerous animals. For many Maasai, tracking is mainly a matter of self-protection. But Kasaine is tracking lions to meet them and to protect them. He leads a small group of wide-eyed tourists over the red sandy path, searching for the lion that has left upon it his prints.

Each year, thousands of tourists crowd Kenya's national parks to try to have a look at the"big five”; elephants, rhinoceros, leopards, buffaloes and lions. The international draw of these animals matters a lot because the nation's economy is tied to the protection of its wildlife. If Kenya's wildlife disappears, so does its second-largest source of income.

    Wildlife protection efforts in Kenya meant marking off land exclusively(专门地)for animals. But it also meant that the people who had originally lived in the area were forced to leave their land and into smaller surrounding areas. They are also finding it increasingly hard to keep a traditional Maasai lifestyle. But people are glad that it really makes a difference to wildlife protection.

    Schools across the world are trying to come up with solutions to keep students active. Some are replacing traditional classroom chairs with exercise balls or standing desks. At Ward Elementary School in Winston, North Carolina students have adopted a new program that requires riding fixed bikes while reading.

    'Read and Ride5 is the creation of school counselor Scott Ertl, who came up with the idea while he was exercising and reading at the gym. Believing it would be a fun way to convince students to become more active, he placed one in the comer of his classroom and encouraged them to use it during independent reading classes.

    It was so popular that Ertl decided to add more bikes and offer the Read and Ride program to the entire school. Today Ward Elementary has a dedicated exercise room filled with bikes that can be used by students while completing their daily reading assignments.

    Besides making reading more fun, the program also helps students exercise at a comfortable pace without the pressure that comes with regular sports-related activities. It is also a perfect way to release energy during days when the weather is not helpful to outdoor activities.

    Most importantly, however, are the program's academic benefits. A year after Read and Ride was introduced at Ward Elementary School, students actively involved in the program demonstrated an astonishing 83% reading proficiency. Those that had not taken advantage of the exercise bikes tested at a much lower, 41%.

    Though the substantial improvement in academic achievement cannot all be attributed to programs like Read and Ride, experts believe they are a significant contributor. That's because studies have shown that physical activity stimulates (刺激) brain cells and helps prepare it for learning. As word of the difference made by this easy to execute exercise program spreads, don't be surprised to find schools across the country adopt “Read and Ride” for their students.

    A black hole is created when a large star burns out. Like our sun, stars are unbelievably hot furnaces(熔炉) that burn their own matter as fuel. When most of the fuel is used up, the star begins to die.

    The death of a star is not a quiet event. First there is a huge explosion. As its outer layer is blasted off into space, the dying star shines as brightly as a billion suns.

    After the explosion, gravity pulls in what's left of the star. As the outside of the star sinks toward the center, the star gets smaller and smaller. The material the star is made of becomes tightly packed together. A star is so solid that a teaspoon of matter from it weighs billions of pounds.

    The more the star shrinks(收缩), the stronger the gravity inside it becomes. Soon the star is very tiny, and the gravity pulling it in is unbelievably strong. In fact, the gravity is so strong that it even pulls light into the star! Since all the light is pulled in, none can go out. The star becomes black when there is no light. Then a black hole is born!

    That's what we know about black holes. What we don't know is this: What happens inside a black hole after the star has been squeezed into a tiny ball? Does it keep getting smaller and smaller forever? Such a possibility is hard to imagine.

    But if the black hole doesn't keep shrinking, what happens to it? Some scientists think black holes are like doorways to another world. They say that as the star disappears from our universe, it goes into another universe. In other words a black hole in our universe could turn into a "white hole" in a different universe. As the black hole swallows(吞噬) light, the white hole shines brightly--somewhere else. But where? A different place, perhaps, or a different time--many years in the past or future.

    Could you travel through a black hole? Right now, no. Nothing we know of could go into a black hole without being crushed(挤压). So far the time being, black hole must remain a mystery.

Black holes are a mystery--but that hasn't stopped scientists from dreaming about them. One scientist suggested that in the future we might make use of the power of black holes. They would supply all of Earth's energy needs, with plenty to spare. Another scientist wondered if a black hole could some day be used to swallow earthly waste--a sort of huge waste disposal(处理) in the sky!

    When returning to south-western Germany, where my parents live, it is compulsory for me to go on a hike to connect with nature and reconnect with myself. So, that is exactly what I did the first sunny Sunday back in the beautiful Black Forest. The Huzenbacher See is a tarn in the middle of the northern Black Forest with abundant nature surrounding it. Approaching it after a good hour walk, I saw fascinating blue dragonflies in quantity that attracted us by the way they flew around. They didn't stand still for a photo, as they landed on leaves for a split second. We were also surprised at the yellow water lilies that can be seen floating on its surface between June and July.

    Sitting down at one of the benches surrounding the lake for a picnic was satisfying in two ways. I was aware of the world's beauty that gave me the energy to continue up the mountain to reach the most amazing view looking over the lake. The other was to really fill myself up in order to continue the adventure adequately, full up on some snacks and refreshing water from the well.

    The hike up wasn't as hard as expected and a good path was provided with dirty rocks and slippery stones all under the shade of the tall trees. This took about an hour and a half until reaching the beautiful view of the lake and land below. Once we had taken in the astonishing views, the walk back down took another hour or so, making the hike a 3-to4-hour round trip, which was well worth it!

    Simply being back in the Black Forest and having such pleasant hikes is definitely good for the soul and I highly recommend getting yourself outside, be it in the Black Forest or anywhere outdoors. Get your intake of vitamin D and, most importantly, take in the moments that nature has to offer.

    Alice Moore is a teenager entrepreneur(创业者), who in May 2015 set up her business AilieCandy. By the time she was 13, her company was worth millions of dollars with the invention of a super-sweet treat that could save kids' teeth, instead of destroying them.

    It all began when Moore visited a bank with her dad. On the outing, she was offered a candy bar. However, her dad reminded her that sugary treats were bad for her teeth. But Moore was sick of missing out on candies. So she desired to get round the warning, "Why can't I make a healthy candy that's good for my teeth so that my parents can't say no to it?" With that in mind, Moore asked her dad if she could start her own candy company. He recommended that she do some research and talk to dentists about what a healthier candy would contain.

    With her dad's permission, she spent the next two years researching online and conducting trials to get a recipe that was both tasty and tooth-friendly. She also approached dentists to learn more about teeth cleaning. Consequently, she succeeded in making a kind of candy only using natural sweeteners, which can reduce oral bacteria.

    Moore then used her savings to get her business off the ground. Afterwards, she and her father secured their first business meeting with a supermarket owner, who finally agreed to sell Moore's product—CanCandy.

    As CanCandy's success grows, so does Moore's credibility as a young entrepreneur. Moore is enthusiastic about the candy she created, and she's also positive about what the future might bring. She hopes that every kid can have a clean mouth and a broad smile.

    Meanwhile, with her parents' help, Moore is generally able to live a normal teenage life. Although she founded her company early on in life, she wasn't driven primarily by profit. Moore wants to use her unique talent to help others find their smiles. She donates 10% of AilicCandy's profits to Big Smiles. With her talent and determination, it appears that the sky could be the limit for Alice Moore.