Astronomy (天文学) is the oldest science known to man. Thousands of years ago man looked at the stars and wondered about heavens(天堂). But the six planets that he could see with his eyes alone limited man.

    The Greeks studied astronomy over 2,000 years ago. They could see the size, color, and brightness of a star. They could see its place in the sky. They watched the stars move as the seasons changed. But the Greeks had no tools to help themselves study the heavens.

    Each new tool added to the field of astronomy helped man reach out into space. Until there were telescopes(望远镜), man did not know much about the moon. He did not know that the planet called Saturn(土星) had rings around it. His sight was so limited that he could not see all the planets. In the early 1700s, people thought there were only six planets. Pluto (冥王星), the last of the nine planets to be discovered was seen until 1930.

    Before the spectroscopes (分光镜), man didn't know what kind of gas was in the sun or other stars, without radio telescopes(射电望远镜), we did not know that radio noise came from far in space.

    Today, astronomy is a growing science. We have learned more in the past fifty years than in the whole history of astronomy.

    A great invention by an 18-year-old high school student grew out of a simple problem most teenagers meet with.

    “I'm a teenager and I have a cellphone and my cellphone battery always dies，so I was really looking for a way to improve energy storage，” Eesha Khare said on Tuesday. “That's how I came across the super capacitor.”

    The teenager who came from California, and graduated from high school last week，won a $50，000 prize on May 17，2013 at the Intel International Science and Engineering Fair for creating a device that can store enough energy to charge a cellphone in 20 to 30 seconds.

    “It charges very quickly and can store a lot of energy，” Khare said. “The cool thing is that it's a lot thinner than one strand of hair.”

    Khare hasn't used her invention to recharge a cellphone yet，but she used it to power a light-emitting diode (LED) in order to show its capability(容量). If used on cellphones，the supercharger would slide on to the phone's battery to juice it up in a matter of seconds. The technology isn't available to consumers yet，and it could be years until it is.

    At an Intel event in Phoenix，Khare won the Intel Foundation Young Scientist Award，taking second place overall in the world's largest high school science research competition. She beat out more than 1，600 finalists from 70 countries. She said that she has been approached by several companies to continue her research，but she is now focused on attending Harvard University in autumn.

    “Right now，just my education，but hopefully we'll see what happens in the future，” she said about her plans. “I have a lot of interests，so we'll see what I do in the future.”

    A week ago at Compton Elementary School, Georgia, something wonderful happened. Band students from Hillgrove High School arrived to hang out with and talk to the little guys. They wanted to make sure the school's youngest had food in their homes that week.

    The thing that thrilled people was that this generous idea came from 17-year-old Nathan Jones, not an adult. Jones is a good trumpet (小号) player with the Hillgrove Hawks band. The idea, he said, came to him two years ago during a discussion about community service in a freshman leadership class. Serving the community was nothing new to Jones. For years, he and his family, who recently moved from Orlando, Florida, had been active community volunteers.

    Last year, Jones thought it was a good idea to get the school band involved in community service, only for the young kids in the school. Band director Patrick

    Erwin agreed but decided they had neither the time nor the resources to do it. "It got put on the back burner," Jones said. "This year, I decided to try again." This time, Erwin encouraged Jones to take charge and he did.

    Back in August, Jones challenged the band to raise $5, 000 to help with the cost of packing the meals. Within two weeks, they'd collected $6, 000 in donations, enough to provide 2,500 family meals, including bags of rice, soy protein, vitamins and vegetables. By the end of the month, when poor families are struggling, a bag of food can mean the difference between a full stomach and an empty one for many of those students.

    But HiHgrove's effort isn't just about feeding the body. It's about feeding souls, too.

    Early on, the band's goal was to direct students' focus from getting "likes" on social media to building relationships with the people around them. So the band decided on the message, "What the world needs now is love, not likes" for its half-time show.

    "That means actually going into the community and actually showing love," Jones said. "We're going out and doing what we're telling people to do."

    Still seeking a destination for your weekend break? There are some places which are probably a mere walk away from your college.

    King's Art Centre

    A day at the Centre could mean a visit to an exhibition of the work of one of the most interesting contemporary artists on show anywhere. This weekend tees the opening of an exhibition of four local artists.

    You could attend a class teaching you how to 'learn from the masters' or get more creative with paint—free of charge.

    The Centre also runs two life drawing classes for which there is a small fee.

    The Botanic Garden

    The Garden has over 8, 000 plant species; it holds the research and teaching collection of living plants for Cambridge University.

    The multi-branchedTorch Aloe here is impressive. The African plant produces red flowers above blue-green leaves, and is not one to miss.

    Get to the display house to seeDionaea muscipula, a plant more commonly known as the Venus Flytrap that feeds on insects and other small animals.

    The Garden is also a place for wildlife-enthusiasts. Look for grass snakes in the lake. A snake called 'Hissing Sid' is regularly seen lying in the heat of the warm sun.

    Byron's Pool

    Many stories surround Lord Byron's time as a student of Cambridge University, Arriving in 1805, he wrote a letter complaining that it was a place of "mess and drunkenness". However, it seems as though Byron did manage to pass the time pleasantly enough. I'm not just talking about the pet bear he kept in his roans. He spent a great deal of time walking in the village.

    It is also said that on occasion Byron swam naked by moonlight in the lake, which is now known as Byron's Pool. A couple of miles past Grantchester in the south Cambridgeshire countryside, the pool is surrounded by beautiful circular paths around the fields. The cries of invisible birds make the trip a lovely experience and on the way home you can drop into the village for afternoon tea. If you don't trust me, then perhaps you'll take it from Virginia Woolf—over a century after Byron, she reportedly took a trip to swim in the same pool.

    We lived in a quiet neighborhood. One evening I heard a loud crash. Earlier my wife had asked me to the store for soft drinks. My teenage daughter Holly practiced her driving, so I sent her to the store in my truck.

    At dinner my son talked about how much he liked my truck. I enjoyed having it, but I said: "My heart is not set on that truck. I like it but it is just metal and won't last forever. Never set your heart on anything that won't last. "

    After hearing the loud noise, the whole family ran outside. My son shouted: "Holly crashed your truck."

    The accident took place in my own driveway. Holly had crashed my truck into our other vehicle(交通工具), the family van. In her inexperience, she had confused the brake(刹车) and the gas pedal(油门). Holly was unhurt physically, but she was crying, "Dad, I'm sorry. I know how much you love this truck." I held her in my arms as she cried.

    I still remembered how sad Holly was the night she crashed our truck, and how I comforted her. When Holly thinks back on her life, I want her to know that I love her a thousand times more than any piece of property(财产).

    I repaired the van, but the dent(凹痕) in my truck is still there today. Every day it reminds me of what really matters in my life.

Tunnels are passageways that are built under the ground. They can also be made under a sea or a river. Some tunnels are dug through high mountains.

For hundreds of years, tunnels have been built all over the world. People use these tunnels to travel from one place to another. Some tunnels are used as waterlanes. Coal and gemstones are also brought from under the ground through long tunnels.

In the past, people dug tunnels using picks and shovels. Rocks and soil were loaded into one-wheel barrows and then onto horses and carts. This work was very tiring.

Today, engineers do a lot of planning before they start to build a tunnel. They use computers to check the level of the water and the types of rock under the ground. When they are sure the area is safe, huge machines are used to dig out the soil.

These machines have an enormous cutting wheel at the front. The wheel slowly grinds (磨碎) through the rock and soil to make the tunnel. Soil that is not needed is carried away in large trucks. As the tunnel becomes longer, it is lined with huge pipes so the walls and roof do not callapse.

Long tunnels have powerful lights to help drivers see the road ahead. Water sprinklers (洒水装置) are fitted to help keep people safe if a fire breaks out in the tunnel.

In large cities, tunnels are built under very busy roads. , People can drive through these tunnels. This makes it quicker to travel to different parts of the city.

Some trains have to wind slowly and carefully over steep mountain slopes. But, in places where there are tunnels, trains can travel quickly through the mountain to reach the other side.