</p> 第4部分:阅读理解(第31-45题,每题3分,共45分)
/ V& j. Z! N' w6 P/ i q; G 下面有3篇短文,每篇短文后有5道题。请根据短文内容,为每题确定1个最佳选项。% a! f/ p* D8 c
第一篇 m% @) ]) H$ N: x9 Q
The Hyper-X
0 u/ ^. q4 T- P) c0 z% e5 h: C8 u The Hyper-X(超音速飞机)recently broke the record for air-breathing jet planes when it traveled at a Hypersonic speed(超音速)of seven times the speed of sound.That's about 5,000 miles per hour.At this speed,you'd get around the world-flying along the equator (赤道)-in less than 5 hours.7 X& s& \# I+ A0 z' y. l/ ^, @$ n: [
The Hyper-X is an unmanned,experimental aircraft just 12 feet long.It achieves hypersonic speed using a special sort of engine known as a scramjet(超音速冲压式喷气发动机).
$ N B8 n' N; i6 X$ j. Q% i" g For an engine to burn fuel and produce energy,it needs oxygen.A jet engine,like those on passenger airplanes,gets oxygen from the air.A rocket engine typically goes faster but has to carry its own supply of oxygen.A scramjet engine goes as fast as a rocket,but it doesn't have to carry its own oxygen supply.
# @- w6 D, ], u5 u9 a0 g A scramjet's special design allows it to obtain oxygen from the air that flows through the engine.And it does so without letting the fast-moving air put out the combustion(燃烧) flames.However,a scramjet engine works properly only at speeds greater than five times the speed of sound.
8 k1 M% w3 t {! y A booster rocket(助推火箭)carried the Hyper-X to an altitude of about l00,000 feet for its test flight.The aircraft's record-beating flight lasted just 11 seconds;That brief journey on March 27 makes a major milestone on the way to a new breed of very fast airplanes, says Werner J.A.Dahm of the University of Michigan in Ann Arbor.In the future,engineers Predict,airplanes equipped with scramjet engines could transport cargo quickly and cheaply to the brink(边缘)of space.Such hypersonic jets could carry passengers anywhere in the world in just a few hours.5 X* T- V) y5 D
Out of the three experimental Hyper.X aircrafts built for NASA, only one is now left.The agency has plans for another 11-second hypersonic flight, this time at 10 times the speed of sound.! A) R2 U) I' n) t( F
31 The Hyper-X broke the record because- M5 a) \* I2 _% c* E
A it was the first air-breathing jet plane./ b+ m' w/ h I8 Q
B it flew along the equator.5 c/ X/ a; ?' U- f- V; b% H% I
C it traveled at the speed of sound.% q0 W( H$ c4 f( F: K2 x# n
D it reached a speed of about 5, 000 miles per hour,
2 ~: t' D' u z+ s) b 32 What kind of engine did the Hyper-X use?. X' t, T. j, r% ?1 N
A A jet engine that carries its own oxygen supply.
) d5 n4 \5 n% P) e% w8 [# H. s8 ? B A jet engine that uses no oxygen.
% `) t; E) z3 [+ m4 k3 N C A scramjet engine that doesn't carry its own oxygen supply.& n5 j8 c" C# O0 X1 _; U
D A rocket engine that carries its own oxygen supply.
1 I& T5 ^, G6 E4 n2 H) |$ } 33 Which of the following is NOT true of the scramjet engine?/ D2 T3 ~* t5 p8 v2 m$ `1 `
A It has been used on passenger planes.
9 W, K' _$ m; L( C: W B The air it breathes does not put out the combustion flames. ~3 F9 k$ v% @4 } ?2 E
C It works at speeds greater than five times the speed of sound.
9 g" }' o7 p& b1 f3 P4 m D It goes as fast as a rocket.
4 w& b& q4 N& I 34 What does Werner J.A.Dahm say about the Hyper-X test flight?
9 p; K1 {# G' M# c A It was unsuccessful because it lasted only 11 seconds., q. P$ j5 X) P: C3 z" @% l( c! N
B It is a very important event in developing very fast airplanes.
2 d- e* T* Q' d" O7 r; F7 G9 `: C C,It allows people to fly at an altitude of 100,000 feet.
$ H' ?" U/ h+ J2 g D It can transport cargo quickly and cheaply to outer space.
' h" D) s f5 t9 s2 j8 Z0 E2 y 35 What does NASA plan to do?
4 B: v; y7 d' w) f& } O; q A To build one more Hyper-X aircraft.. u: y- d0 R! V+ n
B To carry out three more Hyper-X experiments.
- y# Y/ D/ }. K/ w$ ?; e: h C To make the aircraft fly higher and longer.
' a, ]+ o: F, u( J D To test another hypersonic flight at 10 times the speed of sound.
6 \( u! S! ^ c7 a. T 第二篇$ ], R/ [' b+ p6 w! M$ N2 A
Stop Eating Too Much
. _4 T1 t% R: ~, j1 u7 [ "Clean your plate!" and" Be a member of the clean-plate club! " just about every kid in the US has heard this from a parent or grandparent.Often, it's accompanied by an appeal:" Just think about those starving orphans(孤儿)in Africa!" Sure,we should be grateful for every bite of food.Unfortunately, many people in the US take too many bites.Instead of staying "clean the plate", perhaps we should save some food for tomorrow.
1 G& L8 Q: ~% t According to news reports, US restaurants are partly to blame for the growing bellies(肚子).A waiter puts a plate of food in front of each customer, with two to four times the amount recommended by the government,according to a USA Today story.Americans traditionally associate quantity with value and most restaurants try to give them that.They prefer to have customers complain about too much food rather than too little.; T& G. y/ X( x7 X$ R
Barbara Rolls,a nutrition(营养)professor at Pennsylvania State University,told USA Today that restaurant portion sizes began to grow in the l970s, the same time that the American waistline(腰围)began to expand.
9 A3 i0 ?# |4 e/ N Health experts have tried to get many restaurants to serve smaller portions.Now,apparently,some customers are calling for this too.The restaurant industry trade magazine QSR reported last month that 57 percent of more than 4,000 people surveyed believed restaurants served portions that were too large;23 percent had no opinion;20 percent disagreed.But a closer look at the survey indicates that many Americans who can't afford fine dining still prefer large portions.Seventy percent of those earning at least $150,000 per year prefer smaller portions;but only 45 percent of those earning less than $25,000 want smaller. `( D& S$ s5 B5 c8 x
It's not that working class Americans don't want to eat healthy.It's just that, after long hours at low-paying jobs,getting less on their plate hardly seems like a good deal.They live from paycheck(薪金支票)to paycheck, happy to save a little money for next year's Christmas presents.
% ], ~- G! I6 L) k- \5 f4 O 36 Parents in the United States tend to ask their children
4 B$ `: X! F8 D1 k A to save food for tomorrow. y4 n* d9 U& L( E5 [6 M
B to wash the dishes.
( H7 c8 t+ B& M m0 c; ^ C not to waste food.
3 n! y7 u ?9 y; F D not to eat too much.. V6 b( m6 p2 `9 z/ P" O
37 Why do American restaurants serve large portions? d# c: T1 ^0 F0 M. j$ q% ^$ ~( n
A Because Americans associate quantity with value.
" l1 A, D7 t3 ~% y# b9 G% g- t) E B Because Americans have big bellies.
2 z* {/ w, F# O' E C Because Americans are good eaters.
6 O& H0 J) x/ S* K2 V+ y D Because Americans are too weak.
, n, d9 L3 W& ` T7 h7 c8 X* p 38 What happened in the 1970s?, u9 a, P3 I) g
A The US government called on its people to reduce their weight.
9 j4 _9 S" s+ E+ I3 p- { B Health experts persuaded restaurants to serve smaller portions.
8 g: |8 A2 i# a r) B( h$ \7 c1 P ^4 t C The United States produced more grain than needed. X" A+ c7 h$ S0 [
D The American waistline started to expand.% U4 b. G+ s4 e* [
39 What does the survey indicate? k9 S+ q$ N s9 \0 C: ]/ w
A Many low-income Americans want large portions.
( z4 A! X1 m- T( N B Twenty percent of Americans want smaller portions.' X8 H2 g5 r% W+ K
C Fifty-seven percent of Americans want large portions.
4 a) G" [! n6 N2 V0 t: a6 { D Forty-five percent of Americans want smaller portions.6 R! h; a0 o9 {0 O9 {& c6 N
40 Which of the following is NOT true of working class Americans?
- D6 A/ n) i" @! E% P6 i A They work long hours.
" E, w: c% D. ]5 P+ x B They live from paycheck to paycheck.
& k3 D8 s" ~5 d# q1 Z1 `9 K C They don't want to be healthy eaters.
; W$ j! Y1 c2 [, o S, v
3 V' S9 q3 z8 H z$ ?: B9 z( F8 C. X D They want to save money for presents. |