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A little airplane has given new meaning to the term going hyper. The Hyper-X is an unmanned，experimental aircraft just 12 feet long. It achieves hypersonic speed using a special sort of engine known as a scramjet3.It may sound like something from a comic book，but engineers have been experimenting with scramjets since the 1960s. Out of the three experimental Hyper-X aircrafts built for NASA5，only one is now left.The agency has plans for another 11-second hypersonic flight，this time at 10 times the speed of the sound. 1. The Hyper-X broke the record because B it flew along the equator. D it traveled at a supersonic speed. | 
