練習(xí)：
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．
答案與題解：
1． C Hyper-X之所以打破紀(jì)錄是因?yàn)樗娘w行速度是音速的7倍。它不是第一架空氣噴氣式飛機(jī)，也不是第一架超音速飛機(jī)，所以A和D都不對。Hyper-X的試飛并未繞赤道飛行，所以B也是錯(cuò)誤的選擇。
2． B 第四段講了三種發(fā)動(dòng)機(jī)的氧氣來源：噴氣式發(fā)動(dòng)機(jī)是從空氣中汲取氧氣，火箭發(fā)動(dòng)機(jī)必須自攜氧氣，而超音速?zèng)_壓噴氣發(fā)動(dòng)機(jī)則不必白攜氧氣，而這正是Hyper-X使用的發(fā)動(dòng)機(jī)裝置。
3． A 根據(jù)第五段內(nèi)容，B、C、D都是正確的說法。第四段最后一句告訴我們，A的說法是不正確的。
4． D 文章的第六段中，密歇根大學(xué)的研究人員Werner J．A．Dahm說，Hyper-X的試飛成功只是研制一種新式快速飛機(jī)過程中的一個(gè)里程碑(a major milestone on the way to a new breed of very fast airplanes)，而不是新型飛機(jī)的誕生。所以，D是正確選擇，A是錯(cuò)誤選擇。B也不是Werner J．A．Dahm想要表達(dá)的意思。C是其他下程師而不是Werner J．A．Dahm說的話。
5． A 答案可在最后一段找到
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．
答案與題解：
1． C Hyper-X之所以打破紀(jì)錄是因?yàn)樗娘w行速度是音速的7倍。它不是第一架空氣噴氣式飛機(jī)，也不是第一架超音速飛機(jī)，所以A和D都不對。Hyper-X的試飛并未繞赤道飛行，所以B也是錯(cuò)誤的選擇。
2． B 第四段講了三種發(fā)動(dòng)機(jī)的氧氣來源：噴氣式發(fā)動(dòng)機(jī)是從空氣中汲取氧氣，火箭發(fā)動(dòng)機(jī)必須自攜氧氣，而超音速?zèng)_壓噴氣發(fā)動(dòng)機(jī)則不必白攜氧氣，而這正是Hyper-X使用的發(fā)動(dòng)機(jī)裝置。
3． A 根據(jù)第五段內(nèi)容，B、C、D都是正確的說法。第四段最后一句告訴我們，A的說法是不正確的。
4． D 文章的第六段中，密歇根大學(xué)的研究人員Werner J．A．Dahm說，Hyper-X的試飛成功只是研制一種新式快速飛機(jī)過程中的一個(gè)里程碑(a major milestone on the way to a new breed of very fast airplanes)，而不是新型飛機(jī)的誕生。所以，D是正確選擇，A是錯(cuò)誤選擇。B也不是Werner J．A．Dahm想要表達(dá)的意思。C是其他下程師而不是Werner J．A．Dahm說的話。
5． A 答案可在最后一段找到