练习:
G( g4 `/ K Z8 q7 C 1. The Hyper-X broke the record because
- T& a' U4 I( T* X A it was the first air-breathing jet plane.
: p+ p- K0 M1 \- h' x& X3 M B it flew along the equator., M/ p. B- f; [- J+ m
C it flew at speeds smaller than five times the speed of sound.
+ f* j0 _7 ?' A+ y D it traveled at a supersonic speed.
$ I! S/ m- Q) L0 I" f0 U d 2. What kind of an engine did the Hyper-X use?
4 Z2 H. L. [: y% H0 a# g A A jet engine that gets oxygen from the air.
( X* q$ G( V% Q/ |/ F0 R9 G/ V B A scramjet engine that doesn’t carry its own oxygen supply.
! x2 l Z0 u; _+ l, w, i C A rocket engine that carries its own supply of oxygen.
+ @9 E, K; B! b D A iet engine that uses no oxygen.1 m& h! `( Y$ A V, u
3. What is NOT true about the scramjet engine?
; S4 Z# o. k% U+ A A It goes slower than a rocket.* V5 u& u- x. N! o$ a
B It extracts oxygen from the air that flows through the engine.
0 E& n' `5 @, r4 M! k C It works only at speeds greater than five times the speed of sound.
1 k6 P( U2 W. l8 c: j3 Z D It doesn’t carry its own oxygen supply.0 V* K# ^1 d! }# l$ E: z, F
4. What did Werner J.A.Dahm of the University of Michigan say about the Hyper-X test flight?
* _. H' G" x( W3 l4 b A It indicated the birth of a very fast airplane.3 A P/ Q7 H$ [* x& h' V. N
B It was self-powered,so it lasted only 11 seconds.
# O4 A) A8 c# g7 ^" H C It can transportcargo quickly and cheaply to the brink of space.2 z( t, ~1 u e- W! _& j* ^/ O
D It is a major milestone in the journey of making a new type of very fast airplanes,
0 u( k0 k8 `$ X6 a 5. What has NASA planned to do?5 L! X- H; v8 O# t# A
A To make another 11-second hypersonic flight at 10 times the speed of the sound.
+ J1 v0 D- r$ ~) z B To make three more Hyper-X experiments.. A6 ?9 o |9 S, W- N: H) V
C To retest the aircraft that is left.
- k: ]. L" [- f; w' a D To make the aircraft fly higher and longer.5 m$ M/ Y! X$ Z; }# b
答案与题解:. C+ m! k0 p' g8 x
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。+ D1 f) z! P; \* R
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。
& [4 F' V8 W7 g) i: z3 ]* L/ b 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。
9 c9 s7 p) P! i* | 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。$ J a8 v: u+ Z6 p, b
5. A 答案可在最后一段找到。 |