On most weekends, you can find Zoe Stone. 8. in front of a computer. But she isn't playing games or watching videos. She's learning how to write code.

    Code is a set of instructions (指令). It tells a computer what to do. Coders are the people who write the instructions for a computer. Coders make websites or apps. Apps can be used for everything from playing games to checking the weather. Coders solve problems and work together. They know how to think big and small.

    Zoe began to learn coding when she was 4 years old. She uses coding to create art, solve problems and make games. Zoe likes coding because it's creative. "Coding is really fun," she said. "You can show what you think in what you make."

    How does Zoe learn coding? She takes classes at Code. org. The website offers hundreds of free code lessons for kids. In fact, more than 29 million students in 180 countries use it. It hopes to bring coding to even more kids.

    "We believe that every child should have the chance to learn about computers and coding," said Alice Steinglass, the president (负责人) of Code. org. "Computers are part of our world," she said. "It's important for kids to understand how they work."

    Once a king got two nice falcons(猎鹰) from his son. He had never seen such beautiful falcons before. He loved them so much and he ordered the best falconer to train them to fly.

    After several months, the king came to see how the training was going on. He found that one falcon had already been able to fly high in the sky, while the other was staying on the branch(树枝) of a tree quietly, just keeping still.

    The king called all his falconers together and ordered them to try every way they could to make the other falcon fly. But none of them succeeded. One day，while the king was taking walk in the forest, an idea came to his mind. Maybe someone who knew the natural environment well could solve this problem. He sent for a farmer who lived in the forest into his palace to train it at once.

    The next morning, the king saw the other falcon flying above in the sky freely. "It is unbelievable!" shouted the king. "How could you make it happen?"

    The farmer replied, "It's very easy. I just cut off the branch where the falcon rested."

    It is always the same to human beings. We all have "two flying wings" in our hearts as well, but we often seem not to notice them and stay where we are just for safety and comfort. We don't realize we can fly so high and freely until the "branch" we are resting on breaks.

Can knots be a form of art? It is in China. It is used for decoration (装饰) on clothing or to hang on a wall. Skilled knot artists make knots that you might see sold in stores that you can take back with you. 

What Is a Chinese Knot?

A Chinese knot is a knot that is tied and woven (编织) from a single length of rope to be different shapes. Most knots have two cords (粗线) entering the knot from the top and two leaving from the bottom. Each kind of knot is named after its shape or the symbolic meaning that it carries.

Knot artists can use different colors, but they prefer deep red ones. The color red means good luck in China.

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At first, people may have made them to record information before people started to write. One hundred thousand year old tools have been discovered that were probably used to tie and untie knots. 

It is known that they were used for artistic decoration and to express thoughts and feelings in the Tang Dynasty (618—907). The traditional art form was carried on by people as part of their culture.

Ancient and Modern Use of Artistic Knots

Even today, Chinese knots are rich in symbolic meaning, and they hold value when given as gifts or passed down through families. For example, in ancient times and even now, lovers may give a knot as a symbol of their love. The "true love knot" and the "double happiness knot" are given or used at weddings to express love and growing old together. 

Along with being symbolic gifts or messages, knots are still used if people wear traditional Chinese clothing. They are used as jewelry such as earrings and necklaces.

When you cut your skin，you bleed. If a person loses a lot of blood，he will become ill and may die. Blood is very important. People have always known that. At one time some people even drank blood to make them strong!

When doctors understand how blood goes around inside the body，they try ways of giving blood to people who need it. They take blood from the healthy people and give it to people who need it. This is called"blood transfusions". The blood goes from the arm of the healthy person into the of the sick person. 

But there are two problems. First，it does not always work. Sometimes people die when they have blood transfusions. Later，doctors find that we do not all have the same kind of blood. There are four groups﹣O，A，B and AB. We all have blood of one of these groups. They also find that they can give any kind of blood to people of group AB. But they find that they must give A-group blood to A-group people and B-group blood to B-group people. I have O-group blood and the doctor told me that I could give blood to anyone else safely. 

There is another problem. To give blood of the right kind doctors have to find a person of the right blood group. Often they cannot find a person in time. If they have a way to keep the blood until someone needs it，they can always have the right kind of blood. At first they find they can keep it in bottles for fifteen to twenty days. They do this by making it very cold. Then they find how to keep it longer. In the end they find a way of keeping blood for a very long time. 

We call a place where we keep money a"bank". We call a place where we keep blood a"blood bank". One day when you grow up，you may decide to give blood to a"blood bank". In this way you may stop someone from dying. Or perhaps one day you may become ill. You may need blood. 

The"blood bank"will give it to you. 

This famous poem（诗）, Happy Rain on a Spring Night, was written by Du Fu（712—770, the Tang Dynasty）when he was living and farming in Chengdu. His farming experience taught him to be thankful（感谢）to nature and it is shown in this poem. 

The very first word, "good", shows the poet's joy and love for the spring rain. The rain is good because it "knows" the proper time to come. Here the poet uses personification（拟人）, as if the rain was smart enough to come in time for the farmers' busy season. 

When the rain comes, it appears during the night without making any noise. Unlike the summer storms, the spring rain finishes its task without being known. 

In the third couplet（对句）, the poet describes a peaceful scene to us. In the night sky, the clouds look dark and heavy. It's a sign that there will be enough rain during the night. The light from the boat makes the dark scene a bit livelier. 

Lastly, the poet starts to imagine. Tomorrow morning, he thinks, the city of Chengdu will become beautiful when all of the flowers bloom after the rain.