2013年职称英语备考每日练习理工类19_第2页

　　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．
　　词汇
　　hypersonic/7haipE(:)5sCnik/adj．超音速的　　 booster/ 5bu:stE/n．助推器
　　equator/i5kweitE(r)/ n．赤道　　　　　　　　　milestone/5mailstEun/n．里程碑
　　unmanned/Qn5mAnd/adj．无人的 booster rocket 助推火箭
　　scramjet/5skrAmdVet/n．超音速燃烧冲压式， cargo/5kB:^Eu/n．货物
　　喷气发动机
　　combustion/kEm5bQstFEn/n．燃烧 brink/briNk/n．边缘

　练习：
　　1． The Hyper-X broke the record because
　　A it was the first air-breathing jet plane．
　　B it flew along the equator．
　　C it flew at speeds smaller than five times the speed of sound．
　　D it traveled at a supersonic speed．
　　2． What kind of an engine did the Hyper-X use?
　　A A jet engine that gets oxygen from the air．
　　B A scramjet engine that doesn’t carry its own oxygen supply．
　　C A rocket engine that carries its own supply of oxygen．
　　D A iet engine that uses no oxygen．
　　3． What is NOT true about the scramjet engine?
　　A It goes slower than a rocket．
　　B It extracts oxygen from the air that flows through the engine．
　　C It works only at speeds greater than five times the speed of sound．
　　D It doesn’t carry its own oxygen supply．
　　4． What did Werner J．A．Dahm of the University of Michigan say about the Hyper-X test flight?
　　A It indicated the birth of a very fast airplane．
　　B It was self-powered，so it lasted only 11 seconds．
　　C It can transportcargo quickly and cheaply to the brink of space．
　　D It is a major milestone in the journey of making a new type of very fast airplanes,
　　5． What has NASA planned to do?
　　A To make another 11-second hypersonic flight at 10 times the speed of the sound．
　　B To make three more Hyper-X experiments．
　　C To retest the aircraft that is left．
　　D To make the aircraft fly higher and longer．
　　答案与题解：
　　1． C Hyper-X之所以打破纪录是因为它的飞行速度是音速的7倍。它不是第一架空气喷气式飞机，也不是第一架超音速飞机，所以A和D都不对。Hyper-X的试飞并未绕赤道飞行，所以B也是错误的选择。