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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。
a.Choose a proper material.
b.Press the print buton.
c.The 3-D printer spreads the material.
d.Use a computer to design an object.
