You've heard of 3D printing from newspaper and TV programs．It can “print”in plastic，metal，nylon，and over a hundred other materials.3D printing technology has been around since the 1980s，it was not widely used until the early 2010s．The first working 3D printer was created in 1984 by Chuck Hull．

3D printers use many different types of technologies，but they all share one thing in common：they create a three—dimensional(维度的)object by building it layer(层)，by continuing layer, until the whole object is completed．Imagine a baker(面包师)lay down each layer one at a time until the whole cake is formed.3D printing is somewhat similar， but just a bit stricter．How can 3D printers work so well? The most important thing a program，a 3D printer also needs to have instructions for what to print from a computer．It needs a file as well．The file which is a Computer Aided Design (CAD)paper is created with the use of a 3D modeling program．The program creates a paper that is sent to the 3D printer. Along the way，software pieces the design into hundreds，or more likely thousands of layers．The 3D printer builds up one layer at a time，from the bottom to the top，until the object is done．

    3D printings can be used for making many kinds of things such as machine parts， daily life objects，even human organs(器官)using a person's own cells．

Nowadays, Marc．Dillon founds a project which deals with many world famous paintings like Leonardo da Vinci's Mona Lisa, Van Gogh's Sunflower with 3D technology．This project helps the blind people enjoy the fantastic art through touching．In order to provide a good user experience，these 3D paintings have special instruments which can tell people what they touch．

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    Animals grow up in different ways. Some newborn animals are helpless but their mothers protect them. A newborn kangaroo is very small. It is only a few centimeters(cm) long. It closes its eyes and doesn't have hair. It stays safe in its mother' s pouch(育儿袋) for a long time.A newborn monkey can not walk. Its mother carries it everywhere.

Other baby animals can walk soon after they're born. They learn to run with their mothers when danger is near. A baby zebra can run, an hour after it is born.

    Some baby animals are born in a place that is safe. Baby wolves are usually born in big holes with little light. Other baby animals are born in the open. A baby elephant is often born on open land.

    Animals that drink their mothers' milk are called mammals. A mother bear's milk is rich. Baby bears have milk for a few months. This is the same with baby zebras. As baby animals grow, they need solid(固体) food. Baby lions eat what their mother can catch!

    How do animals communicate (交流) with each other? They have special “languages”. In fact, they are using signals (信号). Different signals have different meanings.

    For example, when a bee (蜜蜂) finds food somewhere, it flies home quickly. It can't speak, but it can tell others by dancing. Other bees will know where and how far the food is.

    Some animals show their feelings by making sounds. For example, when a dog is angry, it barks (吠). At this time, you'd better stay away from it. Birds can make several sounds to show different meanings. Sometimes we humans show feelings by making sounds instead of by speaking. For example, when we feel painful (疼痛的), we cry“Oh!”or“Ouch!”.

    We humans have languages and words. We can communicate face to face by speaking. We can write down what happened in order to remember clearly. We can also send (寄) messages to people far away. But animals can't.

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    What's the first thing that you notice when you walk into your favorite restaurant? Is it the smell of fresh pizza, or the sight of your favorite desserts? Food that looks and smells good will probably taste good, but what about sound? Is that important, too?

    Scientists now believe that the taste of food can change when your ears hear different sounds, but it has to be right kind of sound. When you turn on a microwave with popcorn in it, it soon starts to pop. Do you think, "That sounds tasty!"?Not really, you probably think it's nearly ready. But when you smell it, you go to get the salt and the butter. Hearing the popcorn makes you think about it, but smelling it tells you that it tastes good. So what arc the sounds to change the tastes of the things?

    In an experiment(实验)in a fish restaurant, customers(顾客)listened to the sound of the seaside while they ate. Did it make a difference? Yes, it did Listening to the sea seemed to improve the taste of the food. It was fresher and saltier. When the restaurant tried the same experiment with the sound of the farm animals, there was no difference in taste. The results are going to be useful for restaurants. Perhaps they will try to use fewer unhealthy things, like salt and sugar in food With the right music or sounds, perhaps we won't taste the difference.

    Restaurants are also beginning to set a connection(联系)between food and the sound that the packet(包装袋)makes. Pick up a packet of your favorite potato chips, what does it sound like? One restaurant recently changed the material(材料)that they used to make their potato chip packets because experiments show that the packet which makes a right noise will make customers think the potato chips are fresher. Another idea is that a list of music will begin to appear on food packets, so if you don't like your green vegetables, the right music or sounds could help you learn to love them.

    It is said that more than four million people die each year from smoking. That number is increasing. Seven in ten of those deaths are in developing countries. These numbers are frightening.

    Yet people around the world continue to smoke. The Great American Smokeout has been founded for twenty-five years to show the dangers of smoking and provide support for people who decide to stop smoking. The American Cancer Society says all cigarettes damage the body. It warns that smoking even a small number of cigarettes is dangerous. It is not easy to give up smoking forever. However, doctors say they probably will live longer if they do stop smoking. They will feel better and look better. They also will protect the health of family members who breathe their smoke.

    The American Cancer Society says there is not just one right way to stop smoking. Any useful way to stop smoking is worth trying. They may take long walks or spend time in places where smoking is not allowed. Also, they could eat a small piece of fruit instead of having a cigarette.

    The American Cancer Society says the sooner smokers stop smoking, the more they can reduce their chances of getting cancer and other diseases. It says blood pressure returns to normal twenty minutes after smoking the last cigarette. Carbon monoxide (一氧化碳) gas levels in the blood return to normal after eight hours. After one day, the chance of heart attack decreases. After one year, the risk of heart disease for a non-smoker is half that of a smoker.

Stop smoking before smoking stops you!