Now, it seems that artificial intelligence (人工智能) is becoming more and more popular in life, and it has greatly influenced the ways we live, work and play. Can you imagine that you can play table tennis with a robot one day?

    Recently, a scientist has invented a special robot that can be a table, tennis coach. That means people can practice table tennis not only with humans but also with a robot.

    Named Forpheus, the smart table tennis robot is quite special. It can study the movements of human players and the speeds of the ball. In this way, it can exactly judge(判断) the players skill levels(KF). Then it uses the information to change the ways to play. If the players are just beginners, Forpheus will play in a slow and easy way, but if the players are better ones, the robot will play in a faster and more difficult way. What's more, while playing, it encourages players to try their best with words like "Good job!" ," Come on!" and so on. At the same time, it gives some good chance to improve their skills. So it is both a good partner and a clever coach. Science and technology is developing quickly these days and it's hard to imagine what will happen in the future. "In the next 20 years, it will be possible that one robot teaches another to play table tennis or even invents another one!" Takuoya, the inventor of the robot, said.

    There's much to see under the sea, but you need to remember that light behave differently in water than in air. The objects appear closer to you than they exactly are. You might find yourself reaching out to touch something and completely missing it.

    Objects under water will appear larger than they would on the surface, too. Be careful not to tell any stories about the big fish that got away. That fish might not be so big after all! It's just because sometimes things can seem to be as much as about 33 percent bigger in water!

    What's more, in deeper water, colors just don't seem as bright. In fact, it looks as if some colors are missing. Remember the color of an object results from the wavelength (波长) of light that are reflected (反射) from its surface. And light is taken in as it moves down through the water.

    Swimmers wear wet suits to keep warm underwater. Let's take a bright red, yellow, and blue wet suit as an example. These colors are hard to miss on the surface of water. Watch carefully the changes in color as you descend in the water. The red part now looks almost black because the red light wavelengths, the longest among these three colors, are missing. As you go down deeper, the same thing will happen to the yellow part and in the end to the blue part. Even at a place of about 6 to 9 meters underwater, you will look terrible, like a ghost(鬼怪) ! And you have to wait for your return to the surface to enjoy the bright colors again!

The seasons on Earth

    The Earth that we live on is moving all the time. The Earth turns around itself once every 24 hours. This gives us day and night. The Earth also travels around the Sun once every year. This gives us the four seasons. We have spring and summer when our part of the Earth leans (倾斜) towards the Sun. We have autumn and winter when our part of the Earth leans away from the Sun.

    In many places on Earth, there are four seasons in a year. But in some places there are only two seasons. For example, near the North Pole (北极) there are only winter and summer. The winter nights are long. For more than two months you can't see the Sun, even at noon. The summer days are long. For more than two months the Sun never sets, and there is no night. In the tropics (热带地区) there are also two seasons: a rainy season (wet season) and a dry season.

    Many scientists think that the Earth is getting warmer and warmer. If the change continues, the natural world and human society will face danger. Scientists believe human activity is responsible for the climate change. We produce too many greenhouse gases. They keep heat in the air and make the Earth warm.

    Many of the world's governments agree. And they want to solve the problem. So from 7 to 18 December, 2009，they held a conference in Copenhagen, Denmark to talk about global warming and climate change.

    Representatives(代表) from 192 countries and regions went to the meeting. Although they have not reached an agreement, the Copenhagen Accord(《哥本哈根协议》) was an important beginning to save the Earth. It was made by a small group of countries including China，the USA，India, Brazil and South Africa. Some other countries at the conference also showed support.

    What are the key points of the Copenhagen Accord? The accord limits global temperature increases to 2C by 2050. Scientists think it could help the world to avoid serious climate change.

    The accord also says that developed countries must promise to cut greenhouse gas emissions(排放) to the UN by 31 January, 2010. The accord asks developed countries to give money to help developing countries.

    Many countries and organizations are disappointed that the conference didn't reach a legal document(法律文书). And they think the accord is not clear enough about its goals.

African leaders are worried that the goal of a 2℃ global temperature increase isn't good enough, because it will mean a much higher increase in temperature across Africa. This could cause big problems like food and water shortages across the continent.

    Still, UN Secretary General believes the conference was an "improvement".

    "Finally we reached a deal," Ban said," the accord may not be everything everyone had hoped for, but this is an important beginning."

 The Chinese abacus is known as the suanpan. It is {#blank#}1{#/blank#} important part of traditional Chinese culture and sometimes it is known as China's {#blank#}2{#/blank#}( five) great invention. People can use the abacus {#blank#}3{#/blank#} (calculate) at a faster speed, so it has been called"the {#blank#}4{#/blank#}( old) computer in the world".

 To use the abacus correctly, something {#blank#}5{#/blank#} ( be) necessary for you to know. It usually has more than seven rods(杆子). There are two beads(算珠) on each rod in the upper deck(层) and five beads each in the bottom. The beads are usually round and made {#blank#}6{#/blank#} wood. We count the beads by {#blank#}7{#/blank#}( move) them up or down towards the beam (横梁). If you move them towards the beam, you count their value. {#blank#}8{#/blank#}, if you move them away the beam, you can't count their value. The_abacus can be reset(重置) to the starting position quickly, so you can start to count again {#blank#}9{#/blank#}(easy). Today, the use of abacus is still taught in some primary  {#blank#}10{#/blank#} ( school) as part of maths.

 Friends bring us happiness and hope in our lives. Making friends is a skill and the first thing is to know how to get along with others. If you have trouble making friends, maybe I can tell you how to do it.

 Find your own advantages. {#blank#}1{#/blank#} You have our own skills and talents that others don't have. Believe that you are a good person and have something nice to share with others.

 Respect(尊重) others. Everyone has his or her own idea. Learn how to listen to others' ideas without trying to make them accept yours. We need to respect each other, because it increases confidence. {#blank#}2{#/blank#}

 Be kind. If you are kind to others, they will usually be kind to you. {#blank#}3{#/blank#} For example, saying hello to someone new. Most importantly, give your smile to everyone you meet on the way.

{#blank#}4{#/blank#} Learn to accept what you can't change, and work hard to change what you can. Nobody likes hearing your complaint all the time. If you complain too much, others will leave you.

 Never give up. Even if you face some close minded(保守的) people. If you try many times, they may accept you as their friend. And you can try to find someone who will understand you. Believe there are many people who like you.

What else can you do to make friends?(不能与文中内容雷同, 不超过15个词) {#blank#}5{#/blank#}