职称英语理工类阅读理解经典练习(2)

　　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.