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.

　　標(biāo)準(zhǔn)答案： C，B，A，D，A