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    Have you ever had dreams about building a robot? Or putting together a spaceship? Or even seeing your face made out of chocolate? Done. All you need is a 3-D printer.

    The possibilities of 3-D printing seem endless(无穷尽的）.All the user has to do is to design an object on the computer and choose a material to print in. The printers print in hundreds of different materials including glass, sugar and even skin! When the user presses(按）“print", the 3-D printer spreads the materials layer(层）by layer and like magic the object is produced.

    The first 3-D printer was invented in 1986 by an American, Charles Hull. But 3-D printing has only become cheap enough recently for most people to use. Designers now use 3-D printing to create unusual things. The Dutch artist Dirk Vander Kooj prints furniture made from old fridges. And doctors have used 3-D printing to print human body parts! The Telegraph reported in February that scientists from Cornell Medical College even printed a man-made ear.

    But like a lot of new technologies, if 3-D printing gets into the wrong hands, it can be dangerous.

    In 2011 a group of four men in the US used 3-D printing to produce ATM skimmers(提款机盗刷器).These were placed on an ATM and stole over $400,000 from users of the ATM. It is terrible to think that criminals like them might one day use a 3-D printer to print a gun.

    But for better or for worse, 3-D printing has been put into use. In a few years, you'll probably be wondering how you could ever live without your 3-D printer!

根据短文内容，选择最佳选项。

    Science is proving what pet owners have long believed: Dogs understand what we're feeling. Especially, dogs can recognize(识别) the difference between a happy and an angry human face, a study published Thursday in Current Biology suggests.

    It's the first research to show that dogs are sensitive (敏感) to our facial expressions, says the author Ludwig Huber at the University of Veterinary Medicine, Vienna.

    In the Austrian study, 20 different kinds of pet dogs were taught to play a computer game through a series of exercises. In the first step, the dogs were shown two touch screens, one with a circle and one with a square. Through the exercises, they learned that a treat would appear if they chose the right one.

    Eleven of the 20 dogs were able to catch on to rules of the game and make it to the next test, where they were shown photos of happy and angry faces. The dogs were rewarded if they picked certain expression correctly. During the test, the dogs were shown only the upper half or the lower half of a face.

    It was easier to teach the dogs to choose a happy expression than an angry one, suggesting the dogs do indeed understand the meaning behind the expression, Huber says.

    As a test, the dogs were then presented with: the same half of the faces they saw during the training, but from different people， the other half of the faces used in training， the other half of new faces， the left half of the faces used in training.

    In the cases, the dogs chose the right answer 70 to 100 percent of the time.

    Dogs who had been trained to recognize an expression of anger or happiness on the upper part of a face could find the same expression when shown only the lower part. Huber says, "The only possible explanation is that they recall from memory of everyday life how a whole human face looks when happy or angry."

    Dog owners know their pets not only recognize emotions but also understand the feelings.

    American researchers have successfully developed a way to clean waste water without chemicals. The technique uses green plants. The tests were carried out at waste treatment centre. The scientists put plants in narrow containers inside a glass building. One end of each container was a little higher than the other end. Waste water was directed down the containers through the plants' thick roots as we expected. The roots absorbed the waste in the water and used it for food. At the same time the plants produced natural gas. The gas could be collected and sold as fuel(燃料).

    Four places in Florida are already using green plants to clean their waste water.

Hello, everyone! My name is Peter. I like sports. My favourite sport is football. I often play it with my friends after school. We have a good time.

Of the four seasons, I like summer best. It's hot but I can swim with my friends. I can have ice cream. It's cool!

I have a bird and a dog at home. The bird's name is Polly. It's two years old. It's black, blue and red. The dog's name is Snow. It's one year old. It's white. They are my good friends.

Of all the colours, I like blue best. My pens ,pencils, and bed are blue.In my home, my desk and chair are blue too.

Jane Greenall and Paul Greenall are my parents. My mother likes playing table tennis. Her favourite pets(宠物) are cats. My father likes swimming. His favourite pets are dogs.

注意： 语句连贯， 词数80左右。 作文的标题和开头已经给出， 不计入总词数

My New Year's Resolution

New Year is coming soon and it's time to make resolutions. 

注意：（1）短文必须包括表格中的所有要点，并适当发挥；（2）文中不得出现真实的人名和校名；（3）词数：80—100；短文开头已给出，不计入总次数。

In the past, the food at our middle school dining hall was