练习:
" h% c, k! i4 b6 x% ? 1. The Hyper-X broke the record because
5 [* T* S. O% P) k1 ^1 Z A it was the first air-breathing jet plane.
~3 b+ ?$ w" d: r4 f; f B it flew along the equator.
8 t6 d- i( o9 r+ Q/ Q3 h- [7 r C it flew at speeds smaller than five times the speed of sound.
% e1 j, h- v4 ]# \ D it traveled at a supersonic speed.
7 l7 B- M# U, c5 q4 u6 Y5 ^ 2. What kind of an engine did the Hyper-X use?
4 [, h/ t: `, j' e A A jet engine that gets oxygen from the air.
. H2 Q& ]& j+ [" I B A scramjet engine that doesn’t carry its own oxygen supply.
% x! N8 V, W I1 k0 P+ F C A rocket engine that carries its own supply of oxygen.
* Q! o# o6 W. Z& m$ h; W D A iet engine that uses no oxygen.! _" K( o0 ^. P
3. What is NOT true about the scramjet engine?
1 `& A6 P0 [7 m/ s! y+ P/ h' X: f A It goes slower than a rocket.
1 ^0 p3 J. ]# E) j# g B It extracts oxygen from the air that flows through the engine.
' \, x" ?) K- j4 C+ D( x C It works only at speeds greater than five times the speed of sound.$ y( q* t0 i0 L/ ?
D It doesn’t carry its own oxygen supply.0 f) O3 L" M. a4 \2 u1 J
4. What did Werner J.A.Dahm of the University of Michigan say about the Hyper-X test flight?! l/ _9 T$ a! H! E' O2 d
A It indicated the birth of a very fast airplane.
* g: U- E2 x! @+ h) `# V B It was self-powered,so it lasted only 11 seconds.; O% e; b4 w) c
C It can transportcargo quickly and cheaply to the brink of space.
8 P, ?" P; e: t- {1 R D It is a major milestone in the journey of making a new type of very fast airplanes,. h. _& ?3 C+ N5 r7 V
5. What has NASA planned to do?9 ^9 N' z7 k$ j- M
A To make another 11-second hypersonic flight at 10 times the speed of the sound.
# x. y r1 r4 {9 x6 W2 J8 \ B To make three more Hyper-X experiments.1 v: M6 M5 h5 g* ?" D
C To retest the aircraft that is left.+ P- `6 Y4 z! N1 h0 V7 r5 h* L
D To make the aircraft fly higher and longer.
$ Q# J4 ^2 _1 ] 答案与题解:
3 F) V7 R8 p4 w 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。
8 Y) Z8 m# J6 h* D/ \ 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。
, \$ i4 X6 L% ~# `2 H1 T2 ~3 n 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。+ Z1 a# |; S t: H/ v* e7 s1 @
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。
3 Z3 n0 j2 V. J) o+ O- x 5. A 答案可在最后一段找到。 |