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现在大部分马体格高大,奔跑如飞。科学家们已经找到了与现代马相似的动物的前肢骨骼化石,同时也已确定化石中的动物生存的大致时期(如右图所示,各图与其实物比例相同),他们认为这些动物是现代马的祖先。

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    A great invention by an 18-year-old high school student grew out of a simple problem most teenagers meet with.

    “I'm a teenager and I have a cellphone and my cellphone battery always dies,so I was really looking for a way to improve energy storage,” Eesha Khare said on Tuesday. “That's how I came across the super capacitor.”

    The teenager who came from California, and graduated from high school last week,won a $50,000 prize on May 17,2013 at the Intel International Science and Engineering Fair for creating a device that can store enough energy to charge a cellphone in 20 to 30 seconds.

    “It charges very quickly and can store a lot of energy,” Khare said. “The cool thing is that it's a lot thinner than one strand of hair.”

    Khare hasn't used her invention to recharge a cellphone yet,but she used it to power a light-emitting diode (LED) in order to show its capability(容量). If used on cellphones,the supercharger would slide on to the phone's battery to juice it up in a matter of seconds. The technology isn't available to consumers yet,and it could be years until it is.

    At an Intel event in Phoenix,Khare won the Intel Foundation Young Scientist Award,taking second place overall in the world's largest high school science research competition. She beat out more than 1,600 finalists from 70 countries. She said that she has been approached by several companies to continue her research,but she is now focused on attending Harvard University in autumn.

    “Right now,just my education,but hopefully we'll see what happens in the future,” she said about her plans. “I have a lot of interests,so we'll see what I do in the future.”