Flyingoverseas 版 (精华区)
发信人: bonjovi (bonjovi), 信区: Flyingoverseas
标 题: GRE笔试真题No.7-2
发信站: 哈工大紫丁香 (2001年08月26日18:21:50 星期天), 站内信件
Six arms negotiators—M, O, P, R, S, and T—are to be seated at a round
table to discuss disarmament. There are exactly six chairs around the table.
Each negotiator sits facing the center of the table and is directly opposite
a negotiator across the table. The seating arrangement is subject to the
following restrictions:
T cannot sit next to P.
S cannot sit next to M.
R must sit next to M.
If R sits next to S on S's right side, who must sit next to R on R's right s
ide?
M
O
P
S
T
————————————————————————
答案:(A)
Which of the following is an acceptable sequence of negotiators around the t
able?
M, S, R, T, P, O
M, S, T, P, R, O
T, O, P, S, M, R
T, R, M, P, S, O
T, S, R, M, O, P
————————————————————————
答案:(D)
If M sits next to P, which of the following is a complete and accurate list
of
those who can sit next to P on P's other side?
O
O, S
O, S, R
R, S, T
O, R, S, T
————————————————————————
答案:(B)
If T sits next to M and S sits next to R, which of the other negotiators mus
t
sit next to S?
M
O
P
R
T
————————————————————————
答案:(C)
If T sits directly across the table from O, who must sit on either side of P
?
M and O
M and S
O and R
O and S
R and T
————————————————————————
答案:(D)
Contrary to the assumption that modern technology allows us to improve on
nature, it is clear that any major technologically induced changes in a
natural system are likely to be detrimental to that system. If you were to
open the back of your watch, close your eyes, and poke a pencil into the
exposed works, the almost certain result would be damage to the watch.
Living organisms too, when subjected to technological alteration, will
almost certainly be damaged rather than improved.
The argument above is developed by
citing a consensus of opinion about technology among informed observers
projecting the effects of change in a natural system from observation of a
representative case
drawing an analogy between a natural system and a mechanical device
analyzing a natural system in terms of its constituent parts
examining the results of technological innovations of the past
————————————————————————
答案:(C)
The plant called the scarlet gilia can have either red or white flowers. It
had long been thought that hummingbirds, which forage by day, pollinate its
red flowers and that hawkmoths, which forage at night, pollinate its white
flowers. To try to show that this pattern of pollination by colors exists,
scientists recently covered some scarlet gilia flowers only at night and
others only by day: plants with red flowers covered at night became pollinat
ed;
plants with white flowers covered by day became pollinated.
Which of the following, if true, would be additional evidence to suggest tha
t
hummingbirds are attracted to the red flowers and hwkmoths to the white flow
ers
of the scarlet gilia?
Uncovered scarlet gilia flowers, whether red or white, became pollinated at
approximately equal rates.
Some red flowers of the scarlet gilia that remained uncovered at all times
never became pollinated.
White flowers of the scarlet gilia that were covered at night became pollin
ated
with greater frequency than white flowers of the scarlet gilia that were l
eft
uncovered.
Scarlet gilia plants with red flowers covered by day and scarlet gilia plan
ts
with white flowers covered at night remained unpollinated.
In late August, when most of the hummingbirds had migrated but hawkmoths
were still plentiful, red scarlet gilia plants produced fruit more frequen
tly
than they had earlier in the season.
————————————————————————
答案:(D)
The chief executive officer of one of the country's most successful steel
manufacturing firms is amused at the publicity her management practices have
attracted. She thinks managers get too much of the credit for upswings in
their businesses. "A fickle public assumes too easily that managers are
brilliant when demand is strong and idiotic when it is weak," she asserts.
It can be inferred from the statement made by the chief executive officer th
at
she believes which of the following?
A successful manager should attempt to control public opinion.
There are no managers who can justifiably be said to be brilliant.
Her own management practices are likely to be of little value to other
businesses.
The role of managers becomes less important during economic downturns than
it is in relatively prosperous times.
The level of demand for the products of manufacturing firms cannot be
completely controlled by the managers of the firms.
————————————————————————
答案:(E)
问题:从上文可以推断出执行官相信下面哪一个?
读题:某一国家最成功的钢铁生产公司的首席执行官对她的管理习惯吸引公众注意感到
好
笑。她认为,在公司生意好的时候,经理们得到了太多的信任。她断言:变化的
观
众想的太容易了,认为在需求大的时候经理们就是卓越的,而在需求小的时候,
他们就是愚蠢的。
分析:从最后一句话可以看出,执行官认为需求并不是由经理来决定的。
b.没有经理能够被公正地认为是卓越的。
(no太绝对)
c.她自己的管理经验对其他行业很可能没有价值
d.经济低迷时期和经济相对繁荣时期相比,经理的角色变得不重要
(文中没有这样的比较)
e.公司产品需求水平不能够完全被公司经理控制。
Exactly six detectives—S, T, U, X, Y, and Z—take turns watching a suspect.
To minimize the chance that the suspect will observe them or will escape the
ir
surveillance, the detectives will operate according to the following conditi
ons:
There must be exactly two detectives watching the suspect at all times.
Whenever the suspect travels by car, either U or X must be one of the two
detectives watching, but U and X cannot take a turn together.
Whenever the suspect travels by train, either T or Z must be one of the tw
o
detectives watching, but T and Z cannot take a turn together.
If Z is one of the detectives watching the suspect, S must be the other
detective watching the suspect.
S and X cannot take a turn together watching the suspect.
If the suspect is traveling by car, which of the following is a pair of
detectives who could be watching?
S and T
S and X
T and Y
U and X
U and Y
————————————————————————
答案:(E)
If the suspect travels by train and T is not on the of the detectives
watching, the pair watching must be
S and Y
S and Z
U and Z
X and Y
X and Z
————————————————————————
答案:(B)
If Y is one of the detectives watching the suspect, which of the following
CANNOT be the other detective watching the suspect?
S
T
U
X
Z
————————————————————————
答案:(E)
If the suspect travels by car and S is one of the detective watching, the
other detective watching the suspect must be
T
U
X
Y
Z
————————————————————————
答案:(B)
If a pair of detectives was watching while the suspect traveled by car, and
the same pair of detectives continued watching after the suspect began to tr
avel
by train, one member of that pair of detectives must have been
T
U
X
Y
Z
————————————————————————
答案:(A)
A hospital administrator is assigning five patients—N, P, T, V, and X—to
three rooms. Each room has two single beds for patients. The assignment is s
ubject
to the following restrictions:
Patients sharing a room must be of the same sex.
A patient with disease G cannot share a room with a patient who has an inf
ection.
Patients V and X have disease G and no infection.
Patient N has an infection.
Patients P and T each have a broken leg and no other illness or disability
.
Patients N, T, and X are male, and patients P and V are female.
If N shares a room with T, which of the following is true?
None of the patients shares a room with any patient with disease G.
None of the patients shares a room with X.
None of the patients shares a room with any patient with a broken leg.
A patient with a broken leg shares a room with X.
A patient with disease G shares a room with X.
————————————————————————
答案:(B)
If a sixty patient is assigned to the remaining bed, it must be true that th
e
sixth patient
is male
is female or, if male, does not have an infection
has a broken leg
does not have an infection
has disease
————————————————————————
答案:(A)
If Z, a male patient with disease G and no infection, is a newly admitted
sixth patient who is also to be assigned to one of the three rooms, Z must
share a room with
N
P
T
V
X
————————————————————————
答案:(E)
During its manufacture any widget enters an assembly line having exactly
seven consecutively numbered work stations (1 through 7). Each station is
operated by either one human worker or by one robot. Exactly three of the
operators—K, L, and M—are human workers. Exactly two of the operators—R
-1
and R-2—are robots, and each of the robots operates exactly two consecuti
vely
numbered stations.
An entering widget arrives first at station 1 and is subsequently moved
through stations 2, 3, 4, 5, 6, and 7, in that order. However, if at any
station a flaw is detected in a widget, that widget is removed from the
assembly line at the station where the flaw is detected. A flaw in a widge
t
can occur anywhere on the assembly line, and a flaw can be detected at any
station operated by a human worker, with the exception that flaws in widge
ts
cannot be detected at station 1. A widget enters an assembly line on one
occasion only.
Although only human operators can detect flaws in widgets, they do not
necessarily detect every flaw.
Which of the following is a possible set of assignments of operators to stat
ions?
Station Number
1 2 3 4 5 6 7
R-2 R-2 L K M R-1 R-1
R-1 R-2 M R-1 R-2 K L
M R-1 R-1 K R-2 L R-2
L M R-2 R-1 R-2 R-1 K
K L R-1 R-1 R-2 M L
————————————————————————
答案:(A)
If K is assigned to station 7 and L is assigned to station 4, which of
the following must be true?
K but not L could detect a flaw in a widget on the assembly line.
M is assigned to either station 1 or 3.
R-1 is assigned to either station 3 or 5.
R-2 is assigned to stations 5 and 6.
A flaw in a widget that is created at station 3 could be detected at
station 6.
————————————————————————
答案:(B)
If R-2 causes a flaw in a widget at station 4, and the flaw is detected
and the flawed widget is removed from the assembly line at station 6, L coul
d
operate any one of the following stations EXCEPT
1
2
3
5
7
————————————————————————
答案:(B)
If M operates station 6, which of the following must be true?
K operates either station 1 or 7.
L operates either station 3 or 5.
Either K or L operates an even-numbered station.
K and L operate stations that are immediately adjacent to each other.
L operates an odd-numbered station.
————————————————————————
答案:(E)
If R-1 operates station 3 and K is the only operator on the assembly line
who is in a position to detect flaws in widgets that are created by R-1, whi
ch
of the following must be true?
K operates station 4.
K operates station 5.
L operates station 1.
R-1 operates station 4.
R-2 operates station 5.
————————————————————————
答案:(D)
Under an additional rule stipulating that R-1 must operate station 3 or 4
but cannot operate both, and that R-2 must operate station 5 or 6 but cannot
operate both, any of the following would be possible robot assignments EXCEP
T:
R-1 is assigned to station 2, and R-2 is assigned to station 4.
R-1 is assigned to station 3, and R-2 is assigned to station 5.
R-1 is assigned to station 3, and R-2 is assigned to station 6.
R-1 is assigned to station 4, and R-2 is assigned to station 5.
R-1 is assigned to station 5, and R-2 is assigned to station 6.
————————————————————————
答案:(D)
To many environmentalists, the extinction of plants—accompanied by the
increasing genetic uniformity of species of food crops— is the single most
serious environmental problem. Something must be done to prevent the loss of
wild food plants or no longer- cultivated food plants. Otherwise, the lack o
f
genetic diversity could allow a significant portion of a major crop to be
destroyed overnight. In 1970, for example, southern leaf blight destroyed
approximately 20 percent of the United States corn crop, leaving very few
varieties of corn unaffected in the areas over which the disease had spread.
Which of the following can be inferred from the passage above?
Susceptibility to certain plant diseases is genetically determined.
Eighty percent of the corn grown in the United States is resistant to
southern leaf blight.
The extinction of wild food plants can in almost every case be traced to
destructive plant diseases.
Plant breeders focus on developing plants that are resistant to plant disea
se.
Corn is the only food crop threatened by southern leaf blight.
————————————————————————
答案:(A)
Many pregnant women suffer from vitamin deficiency, but this is frequently
not due to vitamin deficiency in their diets; most often it is because they
have higher requirements for vitamins than do the rest of the population.
The best criticism of the reasoning in the statement above is that it
fails to specify the percentage of pregnant women who suffer from vitamin
deficiency
gives insufficient information about why pregnant women have higher vitamin
requirements than do other groups
fails to employ the same reference group for both uses of the term "vitamin
deficiency"
provides insufficient information about the incidence of vitamin deficiency
in other groups with high vitamin requirements
uses "higher requirements" in an ambiguous manner
————————————————————————
答案:(C)
问题:对上文论述中最好的批评是什么?
读题:许多怀孕妇女经常遭受维生素缺乏,但是这通常不是由于他们饮食中的维生素缺
乏,
更经常的是由于她们比其他人有更高的维生素需求。
分析:本题形式我们第一次碰到,它考的是逻辑中的一种错误。就是对于一个词语或一
个
概念,不能够指代两种意思或者出现两种参照对象
文中两次出现VITAMIN DEFICIENCY, 参照对象不同。
第一次说,许多怀孕妇女经常遭受维生素缺乏,指的是怀孕妇女与正常人比,参考对象
是
正常人。正常人也许需要100克/每天,怀孕妇女也许需要150克/每天。
第二次说,这通常不是由于他们饮食中的维生素缺乏,指的是她们吃的食品中的维生素
缺
乏, diets means the sort of food and drink。因此参照对象是正常食品。正常食品
中
也许100克包含10克维生素,但是她们吃的食品中,也许100克只包含5克维生素
Whenever the sun is shining and the windchill factor is below zero, Susan
wears her parka. Whenever it is raining and the windchill factor is above
zero, Susan wears her raincoat. Sometimes it rains when the sun is shining.
If the above statements are true, which of the following must also be true?
If it is not raining and Susan is wearing her parka, the sun is shining.
If the windchill factor is below zero and Susan is not wearing her parka,
the sun is not shining.
If the windchill factor is below zero and it is not raining, Susan is weari
ng
her parka.
If the windchill factor is below zero and it is raining, Susan is wearing
her raincoat.
If it rains while the sun is shining and the windchill factor is zero, Susa
n
wears her parka.
————————————————————————
答案:(B)
Despite the apparently bewildering complexity
of this procedure, the underlying----is quite----.
simplicity.. calculated
principle.. elementary
confusion.. imaginary
purpose.. effective
theory.. modern
————————————————————————
答案:(B)
apparantly: adv.1.清晰可见地 2.显然地,明显地 3.表面上地,貌似(真实)地
bewildering: a.令人困惑的,令人昏乱的
underlying: a.1.在下面的 2.基本的,根本的 3.潜在的,含蓄的,隐晦的
4.底层的,基础的
simplicity: n.1.简单,简易,简明 2.简朴,朴素 3.纯朴,单纯
calculated: a.精心策划的,蓄意的
elementary: a.基本的,(问题等)简单易答的
imaginary: a.假想的,虚构的,想象中的
尽管这一程序表面上具有一种令人困惑的复杂性,但其深层的原理却是相当基本简易。
In television programming, a later viewing time
often----a more----audience and, therefore,
more challenging subjects and themes.
requires.. critical
evinces.. affluent
implies.. mature
eliminates.. realistic
invites.. general
————————————————————————
答案:(C)
challenging: a.1.挑战性的,考验人的 2.激发兴趣(或好奇心)的,令人深思的
theme: n.1.题目,主题 2.(文学作品的)主题思想 3.〔音〕主题,主旋律
critical: a.1.吹毛求疵的,爱挑剔的 2.批评的,批判的,评论性的
3.审慎的,谨严的 4.重大的,关键的
evince: v.1.显示出,表现出 2.唤起,引起
affluent: a.富裕的,丰富的
在电视节目的编排方面,较晚的收视时间常常意味着较为成熟的观众,因此,电视台应
播
放一些较具挑战性的题材和主题。
The cultivation of the emotion of natsukashii,
interpretable as "pleasant sorrow," brings
Japanese to Kyoto in the spring, not to----the
cherry blossoms in full bloom but to----the
fading, falling flowers.
mourn.. exclaim over
honor.. protect
describe.. rejoice over
arrange.. preserve
savor.. grieve over
————————————————————————
答案:(E)
cultivation: n.1.培养,磨练,(人际关系的)培植 2.耕种,耕耘 3.教养,修养,文雅
emotion: n.感情,情绪,感情,激动,激情
cherry: n.樱桃(树)
blossom: n.1.花,(一颗树的)全部花朵 2.开花期 3.生长期,发展期,茂盛期,兴旺期
bloom: n.1.花,(一颗树的)全部花朵 2.开花(期) 3.青春焕发,茂盛时期
fading: a.褪色中的,凋谢中的,衰败中的,消失中的
mourn: v.1.感到痛心(遗憾) 2.表示哀悼服丧
exclaim: v.1.呼喊,惊叫 2.大声叫喊,激烈地表示意见
rejoice: v.1.感到高兴,充满喜悦 2.尽情欢乐,欢庆
savor: v.1.品尝,细嗅 2.欣赏,品味 3.尝到,体验到
对于natcudashii这种情感——该词可翻译成“令人愉悦的忧伤”——的培养,在春天时
节将日本人带至京都,并非意欲去欣赏品味盛开的樱花,却要对那些凋花落英黯然神伤
。
Adam Smith's Wealth of Nations (1776) is still
worth reading, more to appreciate the current---
-of Smith's valid contributions to economics
than to see those contributions as the ----of
present-day economics.
disregard.. outgrowths
reaffirmation.. concerns
relevance.. precursors
acceptance.. byproducts
importance.. vestiges
————————————————————————
答案:(C)
valid: a.1.有根据的,确凿的,令人信服的 2.有效验的,恰当可取的
outgrowth: n.1.长出物,分枝 2.发展结果,后果,产物,副产品
precursor: n.1.先驱 2.前兆 3.产物母体,前身
byproduct: n.副产品,附带产生的后果
vestige: n.残留部分,遗迹,痕迹
亚当·斯密的《国富论》乃至仍值得一读,但更多地是为着欣赏斯密的那些卓有成效的
贡
献目前与经济学的相关性,而非将这些贡献视作当代经济学之前身。
At several points in his discussion, Graves, in
effect, ----evidence when it does not support his
argument, tailoring it to his needs.
addresses
creates
alters
suppresses
substitutes
————————————————————————
答案:(C)
in effect: adv.实质上,实际上
tailor: v.(针对特定目的)作修改,使适应特定需要,使适合
address: v.1.向…作讲话(演说),致信给 2.对付,处理 3.称呼
alter: v.改变,改动,更改,使变样
suppress: v.压制,镇压,查禁,抑制
substitute: v.1.用…代替,代以 2.派…接替,由…替代
在其讨论中的几处地方,格雷夫斯事实上在证据并不能支持其论点时,就对这些证据进
行
改头换面,对其进行更改以便使其适应他的需要。
Regardless of what----theories of politics may
propound, there is nothing that requires daily
politics to be clear, thorough, and consistent—
nothing, that is, that requires reality to conform
to theory.
vague
assertive
casual
vicious
tidy
————————————————————————
答案:(E)
regardless of: prep.不管,无论
propound: v.提出(问题,计划等)…供考虑(或讨论)
conform to:v.1.遵照,适应 2.相似,一致,符合 3.顺从
assertive: a.1.武断的,过分自信的 2.(酒)有浓郁香味的
vicious: a.邪恶的,坠落的,道德败坏的,有恶习的
tidy: a.1.整齐(洁)的 2.有条理,精确的
不管条理明晰的政治学理论所提出的内容是什么,没有任何事情要求日常生活中的政治
做
到清晰、全面和连贯——也就是说,没有任何事情要求现实与理论相吻合一致。
Exposure to sustained noise has been claimed
to----blood pressure regulation in human beings
and, particularly, to increase hypertension, even
though some researchers have obtained
inconclusive results that----the relationship.
sharpen.. conflate
increase.. diminish
aggravate.. buttress
disrupt.. neutralize
impair.. obscure
————————————————————————
答案:(E)
exposure: n.1.暴露,显露 2.揭露,揭发
sustained: a.持续的,经久不衰的
blood pressure regulation: n.血压调节机制
hypertension: n.〔医〕高血压(症),(情绪的)过度紧张
inconclusive: a.1.非决定性的,不确定的,不能使人信服的 2.无最后结果的,无效果
的
conflate: v.合并,混合
aggravate: v.加剧,使恶化,使每况愈下
buttress: v.1.以扶壁加固(或支撑) 2.支持,支撑
disrupt: v.1.使破裂,使分裂,使瓦解 2.扰乱,使中断
neutralize: v.1.使中和,使平衡 2.抵消,使成为无效 3.使中立化
impair: 削弱,减少,损害
obscure: v.1.遮掩,遮蔽 2.使变模糊,混淆
暴露于持续不断的噪音之中已被认为会损害人体内的血压调节机制,尤其会加剧高血压
症,尽管某些研究者已获得一些尚不确凿的结果,使这一关系变得扑朔迷离。
SOLDIER: ARMY::
gas: vapor
music: harmony
ruler: height
negative: exposure
element: compound
————————————————————————
答案:(E)
士兵:军队
气体:蒸汽
音乐:和谐,合声
统治者:高度
底片(否定的):暴光
元素:化合物
SLUR: SPEECH::
erase: drawing
smudge: writing
confuse: puzzle
crumble: construction
decrease: volume
————————————————————————
答案:(B)
急促不清的讲:讲话
抹去:绘画
弄脏,玷污(使模糊):写作,文章
使迷糊:迷惑
弄碎:建设
减小:体积(音量,卷册)
LOCOMOTIVE: FLATCAR::
bus: passenger
airplane: cargo
bicycle: frame
tugboat: barge
automobile: chassis
————————————————————————
答案:(D)
火车头:平板车
公共汽车:乘客
飞机:货物
自行车:框架
拖船:驳船
汽车:汽车底盘
TRICKLE: GUSH::
breathe: exhale
amble: move
stain: blotch
warm: sear
teach: educate
————————————————————————
答案:(D)
滴流:喷涌
呼吸:呼气
漫步:走动
弄脏,玷污:弄脏
温暖:烧焦,烧灼
教学:教育
CHARADE: WORD::
symbol: algebra
joke: riddle
sign: direction
mime: story
lie: truth
————————————————————————
答案:(D)
(用动作等作表示的)字谜:词语
象征,符号:代数
玩笑:谜语
路标(象征):方向
哑剧:故事
谎言:真象
EPAULET: SHOULDER::
ring: finger
tassel: wrist
cravat: waist
sash: neck
poncho: arm
————————————————————————
答案:(A)
肩章:肩膀
戒指:手指
流苏:手腕
领带:腰
腰带:脖子
穗饰披巾(雨衣):手臂
VERNACULAR: PLACE::
landmark: tradition
code: solution
fingerprint: identity
symptom: disease
jargon: profession
————————————————————————
答案:(E)
方言:地方
受保护的文物建筑(标界):传统
密码(准则):解决办法
指纹:本体,正身(一致)
征兆:疾病
行话:专业
HEAT: CALORIES::
liquid: gallons
exercise: energy
steam: pressure
lamp: watts
thermometer: degrees
————————————————————————
答案:(A)
热量:卡路里
液体:加伦
练习:能量
蒸汽:压力
灯:瓦特
温度计:度数
MARTIAL: MILITARY::
basic: simplistic
classic: musical
cosmic: planetary
runic: mysterious
endemic: patriotic
————————————————————————
答案:(D)
军事的:军事的
基础的:简单的
经典的,古典的:音乐
宇宙的:行星的
有神秘性的:神秘的
某地特有的:爱国的
Eight percent of the Earth's crust
is aluminum, and there are hundreds of
aluminum-bearing minerals and vast
quantities of the rocks that contain
(5) them. The best aluminum ore is bauxite,
defined as aggregates of aluminous
minerals, more or less impure, in which
aluminum is present as hydrated oxides.
Bauxite is the richest of all those
(10) aluminous rocks that occur in large
quantities, and it yields alumina, the
intermediate product required for the
production of aluminum. Alumina also
occurs naturally as the mineral
(15) corundum, but corundum is not found
in large deposits of high purity,and
therefore it is an impractical source
for making aluminum. Most of the many
abundant nonbauxite aluminous minerals
(20) are silicates, and, like all silicate
minerals, they are refractory, resistant
to analysis, and extremely difficult to
process. The aluminum silicates are
therefore generally unsuitable
(25) alternatives to bauxite because
considerably more energy is required
to extract alumina from them.
The author implies that a mineral
must either be or readily supply which
of the following in order to be
classified as an aluminum ore?
An aggregate
Bauxite
Alumina
Corundum
An aluminum silicate
————————————————————————
答案:(C)
地球地壳的百分之八为铝(aluminum),而含铝的矿物质则有数百种之多,还有大
量
包含这些矿物质的岩石。最佳的铝矿是铝土矿(bauxite),而所谓“铝土矿”,被定义
为
含铝矿物的总称,这些矿物或多或少并非纯粹,铝于其中作为水合氧化物(hydrated
oxide)存在。铝土矿是所有那些大量出现的含铝岩石中含量最丰富的岩石,它产生氧化
铝(alumina),一种制造铝所必不可少的中间产品。氧化铝亦作为刚玉(corundum)这
种矿物质自然发生,然而,刚玉无法以高纯度、大储量被发现,因此,它不是一种切实
可和的冶炼铝的矿源。在许多储量丰富的非铝土矿(nonbauxite)的含铝矿物中,绝大
部分矿物为硅酸盐(silicate),但如同所有的硅酸盐矿物一样,它们耐溶解,不易分
解,
极难加工。因此,一般而言,铝硅酸盐不适合作为铝土矿的替代物质,因为要从它们中
提炼出氧化铝,需要耗费更多可观的能源。
The passage supplies information for
answering all of the following questions
regarding aluminous minerals EXCEPT:
What percentage of the aluminum in
the Earth's crust is in the form of
bauxite?
Are aluminum-bearing nonbauxite
minerals plentiful?
Do the aluminous minerals found
in bauxite contain hydrated oxides?
Are aluminous hydrated oxides
found in rocks?
Do large quantities of bauxite
exist?
————————————————————————
答案:(A)
地球地壳的百分之八为铝(aluminum),而含铝的矿物质则有数百种之多,还有大
量
包含这些矿物质的岩石。最佳的铝矿是铝土矿(bauxite),而所谓“铝土矿”,被定义
为
含铝矿物的总称,这些矿物或多或少并非纯粹,铝于其中作为水合氧化物(hydrated
oxide)存在。铝土矿是所有那些大量出现的含铝岩石中含量最丰富的岩石,它产生氧化
铝(alumina),一种制造铝所必不可少的中间产品。氧化铝亦作为刚玉(corundum)这
种矿物质自然发生,然而,刚玉无法以高纯度、大储量被发现,因此,它不是一种切实
可和的冶炼铝的矿源。在许多储量丰富的非铝土矿(nonbauxite)的含铝矿物中,绝大
部分矿物为硅酸盐(silicate),但如同所有的硅酸盐矿物一样,它们耐溶解,不易分
解,
极难加工。因此,一般而言,铝硅酸盐不适合作为铝土矿的替代物质,因为要从它们中
提炼出氧化铝,需要耗费更多可观的能源。
The author implies that corundum
would be used to produce aluminum if
corundum could be found that is
not contaminated by silicates
the production of alumina could
be eliminated as an intermediate step
in manufacturing aluminum
many large deposits of very high
quality corundum were to be discovered
new technologies were to make it
possible to convert corundum to a silicate
manufacturers were to realize that the
world's supply of bauxite is not unlimited
————————————————————————
答案:(C)
地球地壳的百分之八为铝(aluminum),而含铝的矿物质则有数百种之多,还有大
量
包含这些矿物质的岩石。最佳的铝矿是铝土矿(bauxite),而所谓“铝土矿”,被定义
为
含铝矿物的总称,这些矿物或多或少并非纯粹,铝于其中作为水合氧化物(hydrated
oxide)存在。铝土矿是所有那些大量出现的含铝岩石中含量最丰富的岩石,它产生氧化
铝(alumina),一种制造铝所必不可少的中间产品。氧化铝亦作为刚玉(corundum)这
种矿物质自然发生,然而,刚玉无法以高纯度、大储量被发现,因此,它不是一种切实
可和的冶炼铝的矿源。在许多储量丰富的非铝土矿(nonbauxite)的含铝矿物中,绝大
部分矿物为硅酸盐(silicate),但如同所有的硅酸盐矿物一样,它们耐溶解,不易分
解,
极难加工。因此,一般而言,铝硅酸盐不适合作为铝土矿的替代物质,因为要从它们中
提炼出氧化铝,需要耗费更多可观的能源。
Traditionally, the study of history
has had fixed boundaries and focal
points—periods, countries, dramatic
events, and great leaders. It also has
(5) had clear and firm notions of scholarly
procedure: how one inquires into a
historical problem, how one presents
and documents one's findings, what
constitutes admissible and adequate
(10) proof.
Anyone who has followed recent
historical literature can testify to
the revolution that is taking place
in historical studies. The currently
(15) fashionable subjects come direct
--
过去太遥远,未来太迷茫。
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