4. What did Werner J.A.Dahm of the University of Michigan say about the Hyper-X test flight?</p>A It indicated the birth of a very fast airplane.7 v4 n+ Z8 v+ b* l
B It was self-powered,so it lasted only 11 seconds.
6 e& G% v% u% WC It can transportcargo quickly and cheaply to the brink of space.) @! ?" T1 U, ]
D It is a major milestone in the journey of making a new type of very fast airplanes,$ j6 b! I, S2 ^
5. What has NASA planned to do?
( a5 I/ p& N. e0 PA To make another 11-second hypersonic flight at 10 times the speed of the sound.( z8 N: v2 E X! @) \) I1 i
B To make three more Hyper-X experiments.1 h. l5 F/ Z2 u" n5 T
C To retest the aircraft that is left.
. B3 k& n; y3 {! T! W6 KD To make the aircraft fly higher and longer.
2 Y" z/ \2 h7 Q, d: k答案与题解:
2 {* \+ U- P+ U1. 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。! j1 f* R+ p% s, H
2. B 第四段讲了三种发动机的氧气来源:喷气式发动机是从空气中汲取氧气,火箭发动机必须自携氧气,而超音速冲压喷气发动机则不必白携氧气,而这正是Hyper-X使用的发动机装置。
G. p! n: F+ X( V# u- G* p2 \3. A 根据第五段内容,B、C、D都是正确的说法。第四段最后一句告诉我们,A的说法是不正确的。, O$ B7 o+ `' R
4. D 文章的第六段中,密歇根大学的研究人员Werner J.A.Dahm说,Hyper-X的试飞成功只是研制一种新式快速飞机过程中的一个里程碑(a major milestone on the way to a new breed of very fast airplanes),而不是新型飞机的诞生。所以,D是正确选择,A是错误选择。B也不是Werner J.A.Dahm想要表达的意思。C是其他下程师而不是Werner J.A.Dahm说的话。 |