生而自由适合高中生拓展阅读的英语美文

2021年1月22日发(作者：dernier)
新东方优美背诵短文
50
篇
Unit50:CellsandTemperature
50. Cells and Temperature

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Cells cannot remain alive outside certain limits of temperature and much narrower
limits mark the boundaries of effective functioning. Enzyme systems of mammals and
birds are most efficient only within a narrow range around 37C;a departure of a few
degrees from this value seriously impairs their functioning. Even though cells can
survive wider fluctuations the integrated actions of bodily systems are impaired.
Other animals have a wider tolerance for changes of bodily temperature.
For
centuries
it
has
been
recognized
that
mammals
and
birds
differ
from
other
animals
in
the
way
they
regulate
body
temperature.
Ways
of
characterizing
the
difference
have
become
more
accurate
and
meaningful
over
time,
but
popular
terminology
still
reflects
the
old
division
into
“
warm- blooded
”
and
“
cold- blooded
”
species;
warm-blooded
included
mammals
and
birds
whereas
all
other
creatures
were
considered
cold-blooded.
As
more
species
were
studied,
it
became
evident
that
this
classification
was
inadequate. A fence lizard or a desert iguana
—
each cold- blooded----usually has a
body
temperature
only
a
degree
or
two
below
that
of
humans
and
so
is
not
cold.
Therefore
the
next
distinction
was
made
between
animals
that
maintain
a
constant
body
temperature,
called
home0therms,
and
those
whose
body
temperature
varies
with
their
environments,
called
poikilotherms.
But
this
classification
also
proved
inadequate,
because
among
mammals
there
are
many
that
vary
their
body
temperatures
during
hibernation. Furthermore, many invertebrates that live in the depths of the ocean
never experience change in the depths of the ocean never experience change in the
chill of the deep water, and their body temperatures remain constant.

细胞与温度细胞只能在一定的温度范围内存活，而进一步保证它们有 效工作的温度范围就更
小了。

哺乳动物和鸟类的酶系统只能在
37
℃左右的很小范围内才能有效工作。
与此相差仅几度的温
度都会大大削弱它们的工作效率。
尽管温度变化更大时细胞仍能存活，但机体系统的整体运行能力却被削弱了。其它动物对体
温的变化有更强的适应性。几个世纪以来，人们就

认识到哺乳动物和鸟类调节体温的方式与其它动物不同。随着时间的推移，人们对这种差
异的描述越来越精确和有意义，但是

暖血动物

和

冷血动 物

这一古老的分类方式至今仍在
大众词汇中有所反映。

暖血动物包 括哺乳动物和鸟类，其它动物统统被视为冷血动物。但是对更多物种进行的研究
表明这种分类显然是不适 当的。美洲一种小型蜥蜴和沙漠鬣蜥同

属冷血动物，但实际上它们的体温通常只比人类的体温 低
1
～
2
度，因此并不是真正的冷血。

因此又出现了恒温 动物
(
即保持恒定体温的动物
)
和变温动物
(
即体温随外界 环境的变化而改
变的动物
)
这一区分方式。但这种分类也不恰当。

因为有不少哺乳动物在冬眠期间会改变体温，而许多生活在深海的无脊椎动物在寒冷的深海
水域中体温并 不变化，而是恒定的。

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新东方优美背诵短文
50
篇
Unit49:Sleep
49 Sleep
Sleet
is
part
of
a
person
’
s
daily
activity
cycle.
There
are
several
different
stages
of sleep, and they too occur in cycles. If you are an average sleeper, your sleep
cycle
is
as
follows.
When
you
fist
drift
off
into
slumber,
your
eyes
will
roll
about
a
bit,
you
temperature
will
drop
slightly,
your
muscles
will
relax,
and
your
breathing
well
slow and become quite regular. Your
brain waves
slow and become quite regular.
Your brain waves slow down a bit too, with the alpha rhythm of rather fast waves 1
sleep. For
the next half hour or so,
as
you relax more
and more,
you will drift down
through stage 2 and stage 3 sleep. The lower your stage of sleep. slower your brain
waves
will
be.
Then
about
40to
69
minutes
after
you
lose
consciousness
you
will
have
reached
the
deepest
sleep
of
all.
Your
brain
will
show
the
large
slow
waves
that
are
known as the delta rhythm. This is stage 4 sleep.
You
do
not
remain
at
this
deep
fourth
stage
all
night
long,
but
instead
about
80
minutes
after
you
fall
into
slumber,
your
brain
activity
level
will
increase
again
slightly.
The
delta
rhythm
will
disappear,
to
be
replaced
by
the
activity
pattern
of
brain
waves.
Your
eyes
will
begin
to
dart
around
under
your
closed
eyelids
as
if
you
were
looking
at something occurring in front of you. This period of rapid eye movement lasts for
some 8 to 15 minutes and is called REM sleep. It is during REM sleep period, your
body
will
soon
relax
again,
your
breathing
will
slip
gently
back
from
stage
1
to
stage
4
sleep----only
to
rise
once
again
to
the
surface
of
near
consciousness
some
80
minutes
later.

睡眠

睡眠是人每天日常活动循环的一部分。人的睡眠分几个阶段，而这些阶段也是循 环发生的。
如果你是一个正常的睡眠者，你的睡眠循环会这样进行。

在你开始昏昏入 睡时，你的眼睛会滚动几下，体温略有下降，肌肉放松，呼吸变得缓慢而有
节奏。除了开始几分钟比较快 的
α
节奏外，脑电波也稍有减缓。

这被称为第一阶段睡眠。在随后约半小时 内，你进一步放松，进入第二和第三阶段睡眠。睡
眠越深入，脑电波就越缓慢。大约在开始睡眠后的40
到

60
分钟，你将进入沉睡状态。这时的脑电波表现为巨大的缓波 ，被称为
δ
节奏。这就是第四
阶段睡眠。但你并不是整夜都保持这种沉睡状态。入睡后 约

80
分钟左右，
你的大脑运动水平会再度略有提高。
δ
节奏消失，
并被脑电波的运动图形取代。
你的眼睛会

在闭着的眼睑下迅速转 动，就好象你在看着眼前发生的什么事情。这种迅速的眼球运动持续
约
8
～
1 5
分钟，这一阶段睡眠被称之为快速眼动
(REM)
睡眠。

在REM
睡眠阶段，你的肢体会很快再度放松，呼吸也再次放慢并变得有节奏，你会轻松地从
第一阶段滑入第四阶段睡眠
-
直到大约
80
分钟后重新接近清醒状态。

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新东方优美背诵短文
50
篇
Unit48:Bacteria
48 Bacteria
Bacteria
are
extremely
small
living
things.
While
we
measure
our
own
sizes
in
inches
or centimeters, bacterial size is measured in microns. One micron is a thousandth
of a millimeter: a pinhead is about a millimeter across. Rod-shaped bacteria are
usually from two to four microns long, while rounded ones are generally one micron
in diameter. Thus if you enlarged a rounded bacterium a thousand times, it would be
just about the size of a pinhead. An adult human magnified by the same amount would
be over a mile(1.6 kilometer) tall.
Even with an ordinary microscope, you must look closely to see bacteria. Using a
magnification of
100
times, one finds that bacteria are barely visible as tiny rods
or dots.
One
cannot
make out
anything of their structure. Using special
stains, one
can
see
that
some
bacteria
have
attached
to
them
wavy-looking
“
hairs
”
called
flagella.
Others have only one flagellum. The flagella rotate, pushing the bacteria through
the
water.
Many
bacteria
lack
flagella
and
cannot
move
about
by
their
own
power,
while
others can glide along over surfaces by some little-understood mechanism.
From the bacteria point of view, the world is a very different place from what it
is to humans. To a bacterium water is as thick as molasses is to us. Bacteria are
so small
that they are influenced by
the
movements of the chemical molecules
around
them.
Bacteria
under
the
microscope,
even
those
with
no
flagella,
often
bounce
about
in the water. This is because they collide with the watery molecules and are pushed
this way and that. Molecules move so rapidly that within a tenth of a second the
molecules
around
a
bacteria
have
all
been
replaced
by
new
ones;
even
bacteria
without
flagella are thus constantly exposed to a changing environment.

细菌细菌是极其微小的生物体。我们用英寸或厘米来测量自己的大小，而测量细菌却要用微
米。 一微米等于千分之一毫米。针头直径大约一毫米。

棒状细菌通常有
2
～4
微米长，
而圆形细菌的直径一般只有
1
微米。
因此，
即使你把一个圆形
细菌放大
1000
倍，它也不过一个针头那么大。

可是如果把一个成年人放大
1000
倍，
就会变成
1
英里
(
或
1.6
公里
)
多高。
用一般的显微镜观
察细菌 时，你必须仔细观察才能看见它们。使用

100
倍的显微镜时，你会发现细菌不过是 隐约可见的小细棒或小点点，而它们的结构你却根
本看不出来。使

用特殊的着色剂后 ，你会发现有的细菌上长着不少波状的

毛发

即鞭毛，而有的细菌只有一
根鞭毛。鞭毛的旋转可以推动细菌在水中行进。

不少细菌没有鞭毛，因而不能自己行进。还 有些细菌却能通过某些鲜为人知的机制沿物体表
面滑动。我们所熟知的世界在细菌眼中完全是另一个样子 。

对于细菌来说，水就同糖浆之于人类一样稠密。细菌是如此的微小，周围化学分子的一举一
动都会对它们产生影响。在显微镜下，细菌，甚至包括那些没有鞭

毛的细菌，经常在 水中跳来跳去。这是因为它们与水分子相撞后，被弹向各个方向。分子移
动很迅速，仅
0.1
秒之隔，一个细菌周围的分子就会完全更新。因此，即使是没有鞭毛的细菌也暴露在一个不
断变 化的环境中

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新东方优美背诵短文
50
篇
Unit47:Folk Culture
47 Folk Cultures
A folk culture is a small isolated, cohesive, conservative, nearly self-sufficient
group that is homogeneous in custom and race with a strong family or clan structure
and highly developed rituals. Order is maintained through sanctions based in the
religion
or
family
and
interpersonal.
Relationships
are
strong.
Tradition
is
paramount, and change comes infrequently and slowly. There is relatively little
division
of
labor
into
specialized
duties.
Rather,
each
person
is
expected
to
perform
a
great
variety
of
tasks,
though
duties
may
differ
between
the
sexes.
Most
goods
are
handmade
and
subsistence
economy
prevails.
Individualism
is
weakly
developed
in
folk
cultures
as
are
social
classes.
Unaltered
folk
cultures
no
longer
exist
in
industrialized countries such as the United States and Canada. Perhaps the nearest
modern
equivalent
in
Anglo
America
is
the
Amish,
a
German
American
farming
sect
that
largely renounces the products and labor saving devices of? the industrial age. In
Amish areas, horse drawn buggies still serve as a local transportation device and
the faithful are not permitted to own automobiles. The Amish
’
s central religious
concept of Demut?
“
humility
”
, clearly reflects the weakness of individualism and
social class so typical of folk cultures and there is a corresponding strength of
Amish group identity. Rarely do the Amish marry outside their sect. The religion,
a variety of the Mennonite faith, provides the principal mechanism for maintaining
order.
By
contrast
a
popular
culture
is
a
large
heterogeneous
group
often
highly
individualistic
and
a
pronounced
many
specialized
professions.
Secular
institutions
of control such as the police and army take the place of religion and family in
maintaining order, and a money- based economy prevails. Because of these contrasts,
“
popular
”
may
be
viewed
as
clearly
different
from
“
folk
”
.
The
popular
is
replacing
the folk in industrialized countries and in many developing nations. Folk-made
objects give way to their popular equivalent, usually because the popular item is
more quickly or cheaply produced, is easier or time saving to use or leads more
prestige to the owner.
?????????????????? ?????????????????????????????????????????????????? ???????????
民间文化民间文化是小型的、孤立的、紧密的、保守的、近乎自给自足的群 体，具有同样的
习俗、同样的人种和强有力的家庭或部族结构以及高度发展的宗教仪式。
秩序由宗教或家庭的约束来维持，成员间的关系非常紧密，传统至高无上，很少有变动且变
动缓慢。 劳动专业分工相对较少。

每个人都要做各类活计，尽管男女两性分工不同。绝大多数物品是手 工制造的，经济一般为
自给自足型。个人主义和社会阶层在民间文化群体中的发展十分

薄弱。在象美国和加拿大这样的工业化国家里，一成不变的民间文化群体已不复存在了。在
当代美洲的 英语区，与民间文化最相似的群体也许算是
Amish
。

Amish
是美国的德裔农耕部落，他们基本上拒绝接受工业时代的大多数产品和节省劳力的设
施。在
A mish
地区，轻

便马车仍是当地的交通工具，信徒们不允许拥有汽车。
A mish
宗教中的核心观念
Demut
即谦
卑典型地反映了在民间文化群中个 人主义和阶级的不发达。

而与此同时，
Amish
对群体的认同性却十分强 。
Amish
人很少和他们宗派以外的人通婚。
其宗
教，作为
Men nonite
信

仰的一种，提供了维护秩序的主要机制。相反，大众文化是包含不同 种族的大群体，通常高
度个性化而且不断在变化。

人际关系冷漠，劳动分工明确，由 此产生了许多专门的职业。世俗的控制机构，比如警察和
军队，取代了宗教和家庭来维持秩序，而且实行 的是货币经济。

由于存在着这些差异，

大众的

与

民间的

可谓大相径庭。在工业化国家以及许多发展中国
家里，大众文化正在取 代民间文化。

民间制造的物品正让位于大众化产品，这通常是因为大众化的物品制造起来更快 、更便宜，
用起来更容易、更方便或者是能给其所有者带来更多的威望。

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新东方优美背诵短文
50
篇
Unit46:Vision

Human vision
like that of other primates
has evolved
in an arboreal
environment.
In
the dense complex world of a tropical forest, it is more important to see well that
to
develop
an
acute
sense
of
smell.
In
the
course
of
evolution
members
of
the
primate
line
have
acquired
large
eyes
while
the
snout
has
shrunk
to
give
the
eye
an
unimpeded
view. Of mammals only humans and some primates enjoy color vision. The red flag is
black to the bull. Horses live in a monochrome world .light visible to human eyes
however occupies only a very narrow band in the whole electromagnetic spectrum.
Ultraviolet
rays
are
invisible
to
humans
though
ants
and
honeybees
are
sensitive
to
them. Humans
though ants and
honeybees are sensitive
to them. Humans have no
direct
perception of infrared rays unlike the rattlesnake which has receptors tuned into
wavelengths longer than 0.7 micron. The world would look eerily different if human
eyes were sensitive to infrared radiation. Then instead of the darkness of night,
we would be able to move easily in a strange shadowless world where objects glowed
with varying degrees of intensity. But human eyes excel in other ways. They are in
fact
remarkably
discerning
in
color
gradation.
The
color
sensitivity
of
normal
human
vision is rarely surpassed even by sophisticated technical devices.

视觉

人类的视觉，和其它灵长目动物的一样，是在丛林环境中进化出来的 。在稠密、复杂的热带
丛林里，好的视觉比灵敏的嗅觉更加重要。

在进化过程中，< br>灵长目动物的眼睛变大，
同时鼻子变小以使视野不受阻碍。
在哺乳类动物中，
只 有人和一些灵长目动物能够分辨颜色。

红旗在公牛看来是黑色的，马则生活在一个单色的世界里。然而，人眼可见的光在整

个光谱中只占一个非常狭窄的频段。人是看不到紫外线的，尽管蚂蚁和蜜蜂可以感觉到。与
响尾蛇不同， 人也不能直接感受到红外线。

响尾蛇的感觉器可以感受波长超过
0.7
微米 的光线。如果人能感受到红外线的话，这世界看
上去将十分不同，而且恐怖。到那时，将与
< br>夜的黑暗相反，我们能轻易地在一个奇异的没有阴影的世界里走动。任何物体都强弱不等地
闪着光 。然而，人眼在其它方面有优越之处。

事实上，人眼对颜色梯度具有非凡的分辨能力。普通人 类的视觉感受色彩的灵敏程度，甚至
连精密的技术装备都很难超越。

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新东方优美背诵短文
50
篇
Unit45:The Source of Energe
source of Energy
A summary of the physical and chemical nature of life must begin, not on the Earth,
but in the Sun; in fact, at the Sun
’
s very center. It is here that is to be found
the source of the energy that the Sun constantly pours out into space as light and
heat. This energy is librated at the center of the Sun as billions upon billions of
nuclei of hydrogen atoms collide with each other and fuse together to form nuclei
of helium, and in doing so, release some of the energy that is stored in the nuclei
of
atoms.
The
output
of
light
and
heat
of
the
Sun
requires
that
some
600
million
tons
of hydrogen be converted into helium in the Sun every second. This the Sun has been
doing for several thousands of millions of year.
The
nuclear
energy
is
released
at
the
Sun
’
s
center
as
high-energy
gamma
radiation,
a form of electromagnetic radiation like light and radio waves, only of very much
shorter wavelength. This gamma radiation is absorbed by atoms inside the Sun to be
reemitted at slightly longer wavelengths. This radiation , in its turn is absorbed
and reemitted. As the energy filters through the layers of the solar interior, it
passes
through
the
X-ray
part
of
the
spectrum
eventually
becoming
light.
At
this
stage,
it
has
reached
what
we
call
the
solar
surface,
and
can
escape
into
space
without
being
absorbed further by solar atoms. A very small fraction of the Sun
’
s light and heat
is emitted in such directions that after passing unhindered through interplanetary
space, it hits the Earth.

能量的来源

概说生命的物理和化学特性必须始于太阳< br>--
确切地说，是太阳的核心，而非地球。能量来自
太阳的核心。

在 这里，太阳不停地以光和热的形式向空间倾泻出能量。数十亿计的氢原子核在太阳的核心
碰撞并且聚变生 成氦。在此过程中一部分原本储存于原子核中的能

量被释放出来。太阳所产生的光和热需要每秒将六亿吨氢转化为氦。这样的转化在太阳中
已经持续几十亿年了。核能在太阳的核心被释放为高能的伽马射线。这是一种电磁射线，就
象光波和 无线电波一样，只是波长要短得多。

这种伽玛射线被太阳内的原子所吸收，然后重新释放为波 长稍长一些的光波。这新的射线再
次被吸收，而后释放。在能量由太阳内

部一层层渗 透出来的过程中，它经过了光谱中
X
射线部分，最后变成了光。在此阶段，能

量到达我们所称的太阳表层，并且离散到空间而不再被太阳原子所吸收。只有很小一部分太
阳的光和热 由此方向释放出来，并且未被阻挡，穿越星空，来到地球。


?
新东方优美背诵短文
50
篇
Unit44:Obtaining Fresh water from icebergs
ing Fresh water from icebergs??
?
The
concept
of
obtaining
fresh
water
from
icebergs
that
are
towed
to
populated
areas
and
arid
regions
of
the
world
was
once
treated
as
a
joke
more
appropriate
to
cartoons
than real life. But now it is being considered quite seriously by many nations,
especially since scientists have warned that the human race will outgrow its fresh
water supply faster than it runs out of food.
Glaciers
are
a
possible
source
of
fresh
water
that
has
been
overlooked
until
recently.
Three-quarters of the Earth
’
s fresh water supply is still tied up in glacial ice,
a reservoir of untapped fresh water so immense that it could sustain all the rivers
of the world for 1,000 years. Floating on the oceans every year are 7,659 trillion
metric
tons
of
ice
encased
in
10000
icebergs
that
break
away
from
the
polar
ice
caps,
more than ninety percent of them from Antarctica.
Huge
glaciers
that
stretch
over
the
shallow
continental
shelf
give
birth
to
icebergs
throughout
the
year.
Icebergs
are
not
like
sea
ice,
which
is
formed
when
the
sea
itself
freezes,
rather,
they
are
formed
entirely
on
land,
breaking
off
when
glaciers
spread
over the sea. As they drift away from the polar region, icebergs sometimes move
mysteriously in a direction opposite to the wind, pulled by subsurface currents.
Because they melt more slowly than smaller pieces of ice, icebergs have been known
to drift as far north as 35 degrees south of the equator in the Atlantic Ocean. To
corral them and steer them to parts of the world where they are needed would not be
too difficult.
The difficulty arises in other technical matters, such as the prevention of rapid
melting
in
warmer
climates
and
the
funneling
of
fresh
water
to
shore
in
great
volume.
But even if the icebergs lost half of their volume in towing, the water they could
provide
would
be
far
cheaper
than
that
produced
by
desalinization,
or
removing
salt
from water.

从冰山中获取淡水把冰山拖到世界上人口稠密的地区和干旱地带，再从中获取淡水，这个想
法曾 一度被认

为是一个笑话，更适合于卡通画，而非现实生活。然而现在，许多国家正相当认真地 考虑这
件事情，特别是在科学家们发出警告之后。

科学家们认为人类将在耗尽粮食之 前首先耗尽淡水资源。冰川是一个直到最近以前一直被忽
视的可能的淡水源。全球四分之三的淡水还锁在 冰川的冰块中。

冰川就是一个蓄水池，
其中未开发的淡水量是如此巨大，
足 够支持全世界的江河
1000
年。
每
年有
7
，
65 9
万亿公吨冰漂流在海洋中。

它们包含在
10
，
000< br>座从极地冰帽中断裂出来的冰山中。这些冰山的
90%
以上来自南极。一
年四季 里，覆盖

在浅层大陆架上的巨大冰川生成了众多冰山。冰山和海水的冰不同，后者是海水自身 结冰形
成的，而冰山则完全是在陆地上形成的。

当冰川伸展到海水中时，冰山就断裂 下来。当漂离极地地区时，冰山有时会在底层洋流的推
动下颇为神秘地逆风移动。由于冰山比小块

的冰融化要慢，
因此有的冰山在大西洋中向北飘到了赤道以南
35
°的地 方。
把冰山蓄拦起来
并拖到世界上需要它们的地方将不会太困难。

有困难的 是其它的技术事宜。比如，如何防止冰山在较暖的气候中迅速融化以及如何把大量
的淡水收集到岸上去。 但是，即便在拖

的过程中冰山失去了一半体积，这样做也远比从海水中脱盐取得淡水便宜。


?
新东方优美背诵短文
50
篇
Unit43:Statistics
tics
There were two widely divergent influences on the early development of statistical
methods. Statistics had a mother who was dedicated to keeping orderly records of
government units (states and statistics come from the same Latin root status) and
a gentlemanly gambling father who relied on mathematics to increase his skill at
playing the odds in games of chance. The influence of the mother on the offspring,
statistics,
is
represented
by
counting,
measuring,
describing,
tabulating,
ordering,
and
the
taking
of
censuses
—
all
of
which
led
to
modern
descriptive
statistics.
From
the influence of the father came modern inferential statistics, which is based
squarely on theories of probability.
Describing
collections
involves
tabulating,
depicting
and
describing
collections
of
data.
These
data
may
be
quantitative
such
as
measures
of
height,
intelligence
or
grade
level------ variables
that
are
characterized
by
an
underlying
continuum---or
the
data
may
represent
qualitative
variables,
such
as
sex,
college
major
or
personality
type.
Large
masses
of
data
must
generally
undergo
a
process
of
summarization
or
reduction
before they are comprehensible. Descriptive statistics is a tool for describing or
summarizing
or
reducing
to
comprehensible
form
the
properties
of
an
otherwise
unwieldy mass of data.
Inferential
statistics
is
a
formalized
body
of
methods
for
solving
another
class
of
problems
that
present
great
of
problems
characteristically
involves
attempts
to
make
predictions using a sample of observations. For example, a school superintendent
wishes to determine the proportion of children in a large school system who come to
school
without
breakfast,
have
been
vaccinated
for
flu,
or
whatever.
Having
a
little
knowledge of statistics, the superintendent would know that it is unnecessary and
inefficient to question each child: the proportion for the sample of as few as 100
children. Thus , the purpose of inferential statistics is to predict or estimate
characteristics of a population from a knowledge of the characteristics of only a
sample of the population.

统计学

统计方法的早期发展受到两种截然不同的影响。统计学有一个

母亲

，她致力 于井井

有条地记录政府机构的文件
(
国家和统计学这两个词源于同一个拉丁 语词根，
status)
，还有
一

个有绅士般的赌博
父亲

，他依靠数学来提高赌技，以便在几率的游戏中取胜。

母亲

对

其子女统计学的影响表现在计数、测量、描述、制表、归类和人口普查。所有这些 导致了现
代描述统计学的诞生。

由于

父亲

的影响 则产生了完全基于概率论原理的现代推理统计学。描述统计学涉及对所收
集数据的制表、制图和描述。这 些数据可以是数量性的数据，

如高度、智商、或者是层级性的数据
--
具有 连续性的变量
--
或数据也可以代表性质变量，如
性别、大学专业或性格类型等等。< br>
数量庞大的数据通常必须经过概括或删减的程序才能为人所理解。描述统计学就是这样一个工具，它对极其庞杂的数据进行描述、概括或删减，

使其变成能为人理解的东西。推理统 计学是一套已定形了的方法体系，它解决的是光凭人脑
极难解决的另一类问题。

这类 问题的显著特点是试图通过取样调查来作出预测。例如，有一位教育督察想知道在一个
庞大的学校系统中 ，不吃早饭就上学的学生、已经做过防感冒

免疫的学生，或其它任何类型的学生占多大比例。 若具备一些统计学的知识，这位督察应明
白，询问每个孩子是没有必要而且没有效率的，只要用
100
个孩子为样本，他就可以相当精确地得出这些孩子占整个学区的比例了。因此，推理统计学的目的就是通过了解一个群

体中一些样本的特性，从而对整个群体的特性进行推测和估算。


?
新东方优美背诵短文
50
篇
Unit42:Coal-fired power plants
-fired power plants
The invention of the incandescent light bulb by Thomas A. Edison in 1879 created a
demand for a cheap, readily available fuel with which to generate large amounts of
electric
power.
Coal
seemed
to
fit
the
bill,
and
it
fueled
the
earliest
power
stations.
(which were set up at the end of the nineteenth century by Edison himself). As more
power
plants
were
constructed
throughout
the
country,
the
reliance
on
coal
increased
throughout the country, the reliance on coal increased. Since the First World War,
coal-fired power plants had a combined in the United States each year. In 1986 such
plants
had
a
combined
generating
capacity
of
289,000
megawatts
and
consumed
83
percent
of the nearly 900 million tons of coal mined in the country that year. Given the
uncertainty
in
the
future
growth
of
the
nearly
900
million
tons
of
coal
mined
in
the
country that year. Given the uncertainty in the future growth of nuclear power and
in the supply of oil and natural gas, coal-fired power plants could well provide up
to 70 percent of the electric power in the United States by the end of the century.
Yet, in spite of the fact that coal has long been a source of electricity and may
remain
on
for
many
years(coal
represents
about
80
percent
of
United
States
fossil-fuel
reserves),
it
has
actually
never
been
the
most
desirable
fossil
fuel
for
power
plants.
Coal contains less energy per unit of weight than weight than natural gas or oil;
it
is
difficult
to
transport,
and
it
is
associated
with
a
host
of
environmental
issues,
among them acid rain. Since the late
1960
’
s problems of
emission control and waste
disposal have sharply reduced the appeal of coal-fired power plants. The cost of
ameliorating these environment problems along with the rising cost of building a
facility
as
large
and
complex
as
a
coal-fired
power
plant,
have
also
made
such
plants
less attractive from a purely economic perspective.
Changes in the technological base of coal-fired power plants could restore their
attractiveness,
however.
Whereas
some
of
these
changes
are
intended
mainly
to
increase
the
productivity
of
existing
plants,
completely
new
technologies
for
burning
coal cleanly are also being developed.

火力发电厂托 马斯
?
爱迪生
1879
年发明的白炽灯导致对便宜、易得、可生产大量电能的 燃料
的需求。

煤似乎符合这个要求，并成为第一批电厂的燃料
(
正 是爱迪生本人在
19
世纪末建造了第一批
电厂
)
。全国到处兴建电厂 时，对煤的依赖加深了。

自第一次世界大战以来，
美国每年约有一半的电力是以煤为 燃料的电厂提供的。
1986
年这些
电厂的总发电能力达到
28
，< br>900
千瓦并且消耗了当年全国开采的九亿吨煤的
83%
。考虑到核能发展以 及石油、天然气供应中
的不确定因素，到本世纪末，火力发电厂仍可能为美国提供多达

70%
的电力。然而，尽管煤长期以来一直是电力的原料之一并且可能会继续如此
(
煤占美国化
石燃料储量的
80%)
，它却不是电厂的理想燃料。

煤 的单位能量含量低于石油和天然气，
而且会导致包括酸雨在内的一系列环境问题。
从
1 960
年以来，排放控制和垃圾处理的问题极大地

削弱了燃煤电厂的魅力。由于减轻 这些环境问题需要大量资金，而且建造庞大复杂的燃煤电
厂的费用不断上涨，也使得这些电厂从经济角度 上不具备吸引力。

改变火力发电厂的基础技术却可能恢复它们的吸引力。虽然某些技术改进是 渐进的，其目的
只是提高现有电厂的生产率，但人们正在开发全新的清洁燃煤的技术。

?
?
?
?
新东方优美背诵短文
50
篇
Unit41:American Black Bears
an black bears
American
black
bears
appear
in
a
variety
of
colors
despite
their
name.
In
the
eastern
part of their range, most of these brown, red, or even yellow coats. To the north,
the
black
bear
is
actually
gray
or
white
in
color.
Even
in
the
same
litter,
both
brown
and black furred bears may be born.
Black bears are the smallest of all American bears, ranging in length from five to
six
feet,
weighing
from
three
hundred
to
five
hundred
pounds
Their
eyes
and
ears
are
small and their eyesight and hearing are not as good as their sense of smell.
Like
all
bears,
the
black
bear
is
timid,
clumsy,
and
rarely
dangerous
,
but
if
attacked,
most can climb trees and cover ground at great speeds. When angry or frightened, it
is a formidable enemy.
Black bears feed on leaves, herbs. Fruit, berries, insects, fish, and even larger
animals. One of the most interesting characteristics of bears, including the black
bear, is their winter sleep. Unlike squirrels, woodchucks, and many other woodland
animals,
bears
do
not
actually
hibernate.
Although
the
bear
does
not
during
the
winter
moths, sustaining itself from body fat, its temperature remains almost normal, and
it breathes regularly four or five times per minute.
Most
black
bears
live
alone,
except
during
mating
season.
They
prefer
to
live
in
caves,
hollow logs, or dense thickets. A little of one to four cubs is born in January or
February after a gestation period of six to nine months, and they remain with their
mother
until
they
are
fully
grown
or
about
one
and
a
half
years
old.
Black
bears
can
live
as
long
as
thirty
years
in
the
wild
,
and
even
longer
in
game
preserves
set
aside
for them.

美国黑熊

美国黑熊虽然被叫做黑熊但却有各种各样的颜色。在它们生活区域的东部，大部分黑熊长有
富有 光泽的黑毛，但在西部，他们则长着棕色、红色甚至是黄色的毛。

在北部，
黑熊其实 长着灰色或白色的毛。
就是在一胎所生的小熊中，
都可能混杂棕毛和黑毛。
黑熊是所有 美洲熊中最小的，
5
～
6
英尺长，
300
～
500
磅重。它们的眼睛和耳朵都很小，他们的视力和听觉不如嗅觉那样好。像所有的熊一样，黑
熊胆 小，笨拙，很少具有危险性。但如果

受到攻击，大部分黑熊会以很快的速度爬上树和奔跑。当 发怒或受惊吓时，黑熊会成为可怕
的对手。

黑熊以树叶、草、树根、水果、浆果、昆 虫、鱼，甚至更大的动物为食。熊类，包括黑熊的
最有趣的一个特点是他们的冬眠。

与松鼠、旱獭和其它别的林地动物不同，熊并不真正地冬眠。虽然熊在冬天的几个月中不吃
东西，靠体内 脂肪维持生命，但它们的体

温保持正常，并有规律地一分钟呼吸
4
或
5
次。除交配季节外，大多数黑熊独自生活。他们
喜欢住在洞里、空心的大木头里或茂密的树 丛里。经过
6
到
9
个月的怀孕期后一胎
1
～
4< br>个小熊在
1
月或
2
月出生。
它们同母熊住在一起，
直 到它们完
全长大，即
1
岁半左右。黑

熊在野外可以活到长达
30
年，在专门的保护区中甚至能活得更长。

新东方优美背诵短文
50
篇
Unit40:Cohesion- tension Theory
40 Cohesion-tension Theory
Atmospheric pressure can support a column of water up to 10 meters high. But plants
can
move
water
much
higher;
the
sequoia
tree
can
pump
water
to
its
very
top
more
than
100 meters above the ground. Until the end of the nineteenth century, the movement
of water in trees and other tall plants was a mystery. Some botanists hypothesized
that the living cells of plants acted as pumps. But many experiments demonstrated
that the stems of plants in which all the cells are killed can still move water to
appreciable
heights.
Other
explanations
for
the
movement
of
water
in
plants
have
been
based
on
root
pressure,
a
push
on
the
water
from
the
roots
at
the
bottom
of
the
plant.
But
root
pressure
is
not
nearly
great
enough
to
push
water
to
the
tops
of
tall
trees.
Furthermore,
the
conifers,
which
are
among
the
tallest
trees,
have
unusually
low
root
pressures.
If water is not pumped to the top of a tall tree, and if it is not pushed to the top
of a tall tree, then we may ask: how does it get there? According to the currently
accepted
cohesion-tension
theory,
water
is
pulled
there.
The
pull
on
a
rising
column
of water in a plant results from the evaporation of water at the top of the plant.
As water is lost from the surface of the leaves, a negative pressure, or tension,
is created. The evaporated water is replaced by water moving from inside the plant
in
unbroken
columns
that
extend
from
the
top
of
a
plant
to
its
roots.
The
same
forces
that
create
surface
tension
in
any
sample
of
water
are
responsible
for
the
maintenance
of these unbroken columns of water. When water is confined in tubes of very small
bore, the forces of cohesion (the attraction between water molecules) are so great
that the strength of a column of water compares with the strength of a steel wire
of the same diameter. This cohesive strength permits columns of water to be pulled
to great heights without being broken.

内聚压力理论

大气压能 够支持
10
米高的水柱，但植物可将水送得更高。美洲红杉就能把水泵到地面以上
10 0
多米高的树顶。直到
19
世纪末，水在树木和其它高大植物中的输送还是一个谜。 一些植物学家假定植物中的活细胞
充当了水泵的角色。但许多实验表明细胞都已死亡的植
物茎干仍能将水输送到相当可观的高度。对于植物中输送水的其它解释都基于根压
--
植物 底
端的根对水的推动。但根压完全不足以将水推到树顶。

况且，最高树木中的松柏只 有很低的根压。如果水不是被泵到高树的树顶，也不是被推到树
顶，那么我们会问：它是怎样

到达树顶的呢
?
根据目前为人们所接受的内聚压力的理论，
水是被拉到上面去 的。
一株植物中
作用于一个正在升高的水柱之上的拉力来自该植物顶部水的蒸发。
< br>由于水从叶子表面丧失，一个负压力，或张力就得以产生。蒸发出去的水被植物里流动的水
代替。 这些水形成

水柱从植物顶端一直延伸到根部。在任何水样中造成表面张力的力支持着这些不断的水柱。
< br>当水被限制在内径很小的管道中时，内聚压力
(
水分子之间的相互吸引力
)是如此之大以致一
支水柱的强度相当于一根直径相同的钢丝的强度。

这种内聚压力使得水柱被拉到非常高的地方而不会断裂。

?
新东方优美背诵短文
50
篇
Unit39:The Salinity of Ocean Waters
39 The Salinity of Ocean Waters
If the salinity of ocean waters is analyzed, it is found to vary only slightly from
place to place. Nevertheless, some of these small changes are important. There are
three basic processes that cause a change in oceanic salinity. One of these is the
subtraction
of
water
from
the
ocean
by
means
of
evaporation---
conversion
of
liquid
water
to
water
vapor.
In
this
manner
the
salinity
is
increased,
since
the
salts
stay
behind. If this is carried to the extreme, of course, white crystals of salt would
be left behind.
The opposite
of evaporation is precipitation, such as rain, by which water is added
to
the
ocean.
Here
the
ocean
is
being
diluted
so
that
the
salinity
is
decreased.
This
may
occur
in
areas
of
high
rainfall
or
in
coastal
regions
where
rivers
flow
into
the
ocean. Thus salinity may be increased by the subtraction of water by evaporation,
or decreased by the addition of fresh water by precipitation or runoff.
Normally, in tropical regions where the sun is very strong, the ocean salinity is
somewhat higher than it is in other parts of the world where there is not as much
evaporation.
Similarly,
in
coastal
regions
where
rivers
dilute
the
sea,
salinity
is
somewhat lower than in other oceanic areas.
A third process by which salinity may be altered is associated with the formation
and melting of sea ice. When sea water is frozen, the dissolved materials are left
behind.
In
this
manner,
sea
water
directly
materials
are
left
behind.
In
this
manner,
sea water directly beneath freshly formed sea ice has a higher salinity than it did
before the ice appeared. Of course, when this ice melts, it will tend to decrease
the salinity of the surrounding water.
In
the
Weddell
Sea
Antarctica,
the
densest
water
in
the
oceans
is
formed
as
a
result
of
this
freezing
process,
which
increases
the
salinity
of
cold
water.
This
heavy
water
sinks and is found in the deeper portions of the oceans of the world.
< br>海水盐度如果我们分析海水的盐度，会发现地区间只有轻微的变化，然而有些小的变化是重
要的。

导致海洋的盐度变化的基本过程有三个，其中之一是通过蒸发的方式即把液态水转化为水蒸< br>气来减少海洋中的水分。这样由于盐留了下来，所以盐度增大。

当然，如果这种方式走 向极端，将会余下白色的盐晶体。与蒸发相反的是降水，如降雨，由
此水被加入海中，海水被稀释，从而 盐度降低。

这种情形会发生在大量降雨的地区，或江河入海岸处。因此，盐度通过蒸发减少水 分而上升
或通过降水或径流增加淡水成分而下降。一般来说，在阳光很

强烈的热带地 区，海水的盐度略高于世界上其它没有热带那样多的蒸发的地区。同理，在江
河稀释海水的海岸地带，海 水盐度略低于其它海区。

第三个可以变更盐度的过程与海洋中冰的形成和融化有关。海水冻结 时，溶于其中的物质被
留了下来。这样，在新形成的海

水冰面的正下方的海水比在冰 形成之前有更高的盐度。当然，当冰融化的时候，会降低周围
水中的盐度。

在南极洲 边缘的威德尔海中，结冰过程增加低温海水的盐度，从而形成了浓度最大的海水。
这些大密度的海水下沉 ，可以在世界海洋的深水域发现。

新东方优美背诵短文
50
篇
Unit38:Topaz
38 Topaz
Topaz is a hard, transparent mineral. It is a compound of aluminum, silica, and
fluorine.
Gem
topaz
is
valuable.
Jewelers
call
this
variety
of
the
stone
“
precious
topaz
”
.
The
best-known
precious
topaz
gems
range
in
color
from
rich
yellow
to
light
brown
or
pinkish
red.
Topaz
is
one
of
the
hardest
gem
minerals.
In
the
mineral
table
of hardness, it has a rating of 8, which means that a knife cannot cut it, and that
topaz will scratch quartz.
The golden variety of precious topaz is quite uncommon. Most of the world
’
s topaz
is white or blue. The white and blue crystals of topaz are large, often weighing
thousands of carats. For this reason, the value of topaz does not depend so much on
its size as it does with diamonds and many other precious stones, where the value
increases about four times with each doubling of weight. The value of a topaz is
largely determined by its quality. But color is also important: blue topaz, for
instance, is often irradiated to deepen and improve its color.
Blue topaz is often sold as aquamarine and a variety of brown quartz is widely sold
as
topaz.
The
quartz
is
much
less
brilliant
and
more
plentiful
than
true
topaz.
Most
of it is variety of amethyst: that heat has turned brown.

黄水晶

黄水晶是一种 坚硬、透明的矿物质。它是铝、硅和氟的化合物。黄水晶宝石价值不菲。珠宝
商把这种石头称为

黄玉

。

最出名的黄玉有各种颜色如深黄色、
淡棕色、浅红色等。
黄水晶是最坚硬的宝石矿中的一种。
在矿石硬度表上，它的硬度为
8< br>，这表明刀子不能割开

它而它可在石英上划痕。金黄色的黄玉品种非常罕见。世界上大 多数的黄水晶是白色或蓝色
的。这些白色或蓝色的黄水晶晶体很大，常常有数千克拉重。
由于这个原因，黄水晶的价值不像钻石和许多其它宝石那样主要依赖于其大小，重量翻一番
价值即上 升约四倍。黄

水晶的价值很大程度上取决于其品质，但颜色也很重要。举例来说，蓝色的黄水 晶常需放射
处理以加深和改善其颜色。

蓝色的黄水晶常被作为海蓝宝石出售，许多种 棕色石英被当作黄水晶广为贩卖。石英光亮度
远小于黄水晶，矿藏储量也远较黄水晶丰富。大多数石英< br>
是一种紫水晶，高温使其变为棕色。

新东方优美背诵短文
50
篇
Unit37:Icebergs
37 Icebergs
Icebergs are among nature
’
s most spectacular creations, and yet most people have
never seen one. A vague air of mystery envelops them. They come into being -----
somewhere ------in faraway, frigid waters, amid thunderous noise and splashing
turbulence, which in most cases no one hears or sees. They exist only a short time
and then slowly waste away just as unnoticed.
Objects of sheerest beauty they have been called. Appearing in an endless variety
of
shapes,
they
may
be
dazzlingly
white,
or
they
may
be
glassy
blue,
green
or
purple,
tinted
faintly
of
in
darker
hues.
They
are
graceful,
stately,
inspiring
-----
in
calm,
sunlight seas.
But they are also called frightening and dangerous, and that they are ----? in the
night, in the fog, and in storms. Even in clear weather one is wise to stay a safe
distance away from them. Most of their bulk is hidden below the water, so their
underwater
parts
may
extend
out
far
beyond
the
visible
top.
Also,
they
may
roll
over
unexpectedly, churning the waters around them.
Icebergs
are
parts
of
glaciers
that
break
off,
drift
into
the
water,
float
about
awhile,
and
finally
melt.
Icebergs
afloat
today
are
made
of
snowflakes
that
have
fallen
over
long
ages of
time. They
embody snows
that drifted down hundreds,
or
many thousands,
or in some cases maybe a million years ago. The snows fell in polar regions and on
cold mountains, where they melted only a little or not at all, and so collected to
great depths over the years and centuries.
As
each
year
’
s
snow
accumulation
lay
on
the
surface,
evaporation
and
melting
caused
the snowflakes slowly to lose their feathery points and become tiny grains of ice.
When new snow fell on top of the old, it too turned to icy grains. So blankets of
snow and ice grains mounted layer upon layer and were of such great thickness that
the
weight
of
the
upper
layers
compressed
the
lower
ones.
With
time
and
pressure
from
above,
the
many
small
ice
grains
joined
and
changed
to
larger
crystals,
and
eventually
the deeper crystals merged into a solid mass of ice.

冰山冰山是大自然最壮观的创造之一，但大多数人却从未看到过冰山，一种朦胧神秘的气氛

笼罩着它们。冰山形成于久远的、寒冷的水体中，而且伴随着雷声轰鸣般的嘈杂和水花汹
涌的风暴，但却无人耳闻目睹。冰山仅存在短短的一段时间就慢慢地悄无声息地融化掉。冰
山具有最 纯粹的美，人们如是说。

冰山呈现出千姿百态，可能白得耀眼，或者是闪耀着蓝色、绿色或紫 色的玻璃般的光芒，或
浓或淡。它们在平静的阳光照耀的海水中显得优雅堂

皇，令人 浮想联翩。但是人们亦把冰山称为恐怖的和危险的。它们的确如此
--
在夜间，雾天
和 风暴肆虐时。

即便是在晴朗的天气里，与它们保持一段安全距离也是明智的。冰山的大部分体 积稳藏于水
下，因此其水下部分的伸展远远超过可见的顶部。冰山也可能出人意

料地 翻滚，剧烈地搅动周围的水体。冰山是冰川的一部分，从冰川断裂漂流进水中，一段时
间后融化。今天的 冰山由多年前降落的雪花形成。

它们的体内是数百年，或数千年，有时甚至是数百万年前的降 雪。这些雪花落在极地或寒冷
的山上，仅有少量融化或根本不融

化，这样经过许多年 或许多世纪后积累了巨大的深度。由于每年的雪花积累在表面之上，蒸
发和融化使得雪花慢慢失去其羽状 尖端而变成微小的冰粒。

当新的雪花降落到旧的表面上，也变成了冰粒。因而雪花覆盖层和冰 粒层层堆积起来直到如
此之大的厚度以致较上层的重量压缩较下层。

在时间和压力的 作用下，许多小冰粒结合到一起变成更大的晶体，最终较底层的晶体合并成
庞大而坚固的冰块。

?
?
新东方优美背诵短文
50
篇
Unit36:Plate Tectonics and Sea-floor Spreading
Tectonics and Sea-floor Spreading
The
theory
of
plate
tectonics
describes
the
motions
of
the
lithosphere,
the
comparatively rigid outer layer of the Earth that includes all the crust and part
of the underlying mantle. The lithosphere(n.[
地
]
岩石圈
)is divided into a few dozen
plates
of
various
sizes
and
shapes,
in
general
the
plates
are
in
motion
with
respect
to
one
another.
A
mid-ocean
ridge
is
a
boundary
between
plates
where
new
lithospheric
material is injected from below. As the plates diverge from a mid-ocean ridge they
slide on a more yielding layer at the base of the lithosphere.
Since the size of the Earth is essentially constant,
new
lithosphere
can be created
at
the
mid-ocean
ridges
only
if
an
equal
amount
of
lithospheric
material
is
consumed
elsewhere.
The
site
of
this
destruction
is
another
kind
of
plate
boundary:
a
subduction
zone.
There
one
plate
dives
under
the
edge
of
another
and
is
reincorporated
into the mantle. Both kinds of plate boundary are associated with fault systems,
earthquakes and volcanism, but the kinds of geologic activity observed at the two
boundaries are quite different.
The
idea
of
sea-floor
spreading
actually
preceded
the
theory
of
plate
tectonics.
In
its
original
version,
in
the
early
1960
’
s,
it
described
the
creation
and
destruction
of
the
ocean
floor,
but
it
did
not
specify
rigid
lithospheric
plates.
The
hypothesis
was substantiated soon afterward by the discovery that periodic reversals of the
Earth
’
s
magnetic field
are recorded
in the
oceanic crust. As magma
rises under the
mid-ocean
ridge,
ferromagnetic
minerals
in
the
magma
become
magnetized
in
the
direction
of
the
magma
become
magnetized
in
the
direction
of
the
geomagnetic
field.
When
the
magma
cools
and
solidifies,
the
direction
and
the
polarity
of
the
field
are
preserved
in
the
magnetized
volcanic
rock.
Reversals
of
the
field
give
rise
to
a
series
of
magnetic
stripes
running
parallel
to
the
axis
of
the
rift.
The
oceanic
crust
thus
serves
as
a
magnetic
tape
recording
of
the
history
of
the
geomagnetic
field
that
can
be
dated
independently;
the
width
of
the
stripes
indicates
the
rate
of
the
sea-floor
spreading.

板块结构与海床扩展

板块结构理论描述 岩石圈的运动。
岩石圈是相对坚硬的地球外层，
包括全部地壳和部分地幔。

岩石圈被划分为几十个大小不同形状各异的板块，一般而言这些板块都处于相对运动之中。
一道中海脊是 板块之间的边界，在那里新的岩石圈的物质从下部注入。

当板块从中海脊脱离时，它们滑向在 岩石圈基部较易变形的地层上。因为地球的大小本质上
是不

变的，只有同等数量的岩石圈物质在其它地方被吞没，新的岩石圈才能生成。销毁旧岩石
圈的地方形成另外一种板块边界：一块潜没的区域。在这里，一块板块潜没到另一板块的边
缘之下并 结合入地幔之中。

两种板块边界均与地层系统、地震以及火山活动有关，但在两种边界处观察 到的诸般地质活
动却迥然不同。海床扩展说实际上早于板块结构理论。在

20
世纪
60
年代它的理论雏形中，描述了海底的生成和毁灭，但没有详细介绍坚硬的岩石圈板块。这个假定不久之后为发现所证实。

该发现表明地球磁场周期性的逆转被记录在海洋 地壳中。当岩浆从中海脊下涌起的时候，岩
浆中的磁铁矿物质按地磁场的方向被磁化。岩
浆冷却并凝固下来后，地磁场的方向和磁极被保留在磁化了的火山岩中。磁场的逆转形成一
系列与断 层轴线平行的条形磁区。

这样海洋壳就扮演了磁带的角色，记录下可以鉴定时间的地磁场的历 史。条形磁区的宽度表
明了海底扩展的速度。

新东方优美背诵短文
50
篇
Unit35:Oil Refining
Refining
An important new industry, oil refining, grew after the Civil war. Crude oil, or
petroleum
–
a
dark,
thick
ooze
from
the
earth
–
had
been
known
for
hundreds
of
years,
but
little
use
had
ever
been
made
of
it.
In
the
1850
’
s
Samuel
M.
Kier,
a
manufacturer
in western Pennsylvania, began collecting the oil from local seepages and refining
it
into
kerosene.
Refining,
like
smelting,
is
a
process
of
removing
impurities
from
a raw material.
Kerosene
was
used
to
light
lamps.
It
was
a
cheap
substitute
for
whale
oil,
which
was
becoming harder to? get. Soon there was a large demand for kerosene. People began
to search for new supplies of petroleum.
The first oil well was drilled by E.L. Drake, a retired railroad conductor. In 1859
he
began
drilling
in
Titusville,
Pennsylvania.
The
whole
venture
seemed
so
impractical and foolish that onlookers called it
“
Drake
’
s Folly
”
. But when he
had
drilled
down
about
70
feet(21
meters),
Drake
struck
oil.
His
well
began
to
yield
20 barrels of crude oil a day.
News of Drake
’
s success brought oil prospectors to the scene. By the early 1860
’
s
these
wildcatters
were
drilling
for
“
black
gold
”
all
over
western
Pennsylvania.
The boom rivaled the California gold rush of 1848 in its excitement and Wild West
atmosphere. And it brought far more wealth to the prospectors than any gold rush.
Crude oil could be refined into many
products. For some years kerosene continued
to
be the principal one. It was sold in grocery stores and door-to-door. In the 1880
’
s
refiners
learned
how
to
make
other
petroleum
products
such
as
waxes
and
lubricating
oils. Petroleum was not then used to make gasoline or heating oil.

炼油

一种重要的新兴工业
--
炼油业在国内战争后成长起来。未加 工的石油，或原油
--
一种深色的
地下的稠浆
--
数百年来一直为大 众所知，但是人们却很少使用过它。

在十九世纪五十年代，
萨缪尔
?M?< br>科尔，
宾西法尼亚西部的一位制造商，
开始从当地的溢出物
中收集石油

并将它炼成煤油。与冶炼矿石一样，石油提炼是一个从未加工的原料中除去杂质的过程。煤
油被 用来点灯。

它是鲸油的一种便宜的替代品，而鲸油正变得越来越难以获得。不久就产生了对煤 油的大量
需求。人们开始寻找新的石油供应。第一口油井为

E?L?
瑞克， 一个退休的火车检票员所钻得。
1859
年他开始在宾西法尼亚的泰特斯维尔钻井。
整 个的这项

冒
险事
业看
起来
是如此不
现实
和愚
蠢以
致旁观者
称之
为

鸭子
的蠢
行
。
(
译者注
：
Drake'sFolly,drake
在这里意含双关，
即指瑞克的名字，
又指该词的本义即鸭子。
)
但当瑞克往 下钻至
70
英尺
(21
米
)
的时候，他发现了石油。他的油 井从此每天生产

20
桶原油。瑞克成功的消息将石油勘探者们吸引到现场。截止到< br>19
世纪
60
年代早期，这些
冒险者为寻找

黑色的< br>
金子

钻探遍了整个宾西法尼亚西部。这项繁荣的事业在刺激性和粗犷的西部气 氛上可与

1848
年的加州淘金热相媲美，
而且它为勘探者带来了远超过淘 金潮的财富。
原油能被提炼成
许多产品。多年以来煤油一直是主要的一种产品。
它在杂货店中出售由人挨户推销。
19
世纪八十九十年代炼油者们懂得了生产其它石油产品 ，
如蜡和润滑油。那时石油还没有被

用来制造汽油或采暖装置用油。

新东方优美背诵短文
50
篇
Unit34:Raising Oysters
34 Raising Oysters
In the oysters were raised in much the same way as dirt farmers raised tomatoes- by
transplanting them. First, farmers selected the oyster bed, cleared the bottom of
old
shells
and
other
debris,
then
scattered
clean
shells
about.
Next,
they
”
planted
”

fertilized oyster eggs, which within two or three weeks hatched into larvae. The
larvae
drifted
until
they
attached
themselves
to
the
clean
shells
on
the
bottom.
There
they remained and in time grew into baby oysters called seed or spat. The spat grew
larger
by
drawing
in
seawater
from
which
they
derived
microscopic
particles
of
food.
Before long, farmers gathered the baby oysters, transplanted them once more into
another body of water to fatten them up.
Until recently the supply of wild oysters and those crudely farmed were more than
enough to satisfy people
’
s needs. But today the delectable seafood is no longer
available
in
abundance.
The
problem
has
become
so
serious
that
some
oyster
beds
have
vanished entirely.
Fortunately,
as
far
back
as
the
early
1900
’
s
marine
biologists
realized
that
if
new
measures were not taken, oysters would become extinct or at best a luxury food. So
they
set
up
well-equipped
hatcheries
and
went
to
work.
But
they
did
not
have
the
proper
equipment or the skill to handle the eggs. They did not know when, what, and how to
feed the larvae. And they knew little about the predators that attack and eat baby
oysters by the millions. They failed, but they doggedly kept at it. Finally, in the
1940
’
s a significant breakthrough was made.
The
marine
biologists
discovered
that
by
raising
the
temperature
of
the
water,
they
could induce oysters to spawn not only in the summer but also in the fall, winter,
and
spring.
Later
they?
developed
a
technique
for
feeding
the
larvae
and
rearing
them
to spat. Going still further, they succeeded in breeding new strains that were
resistant
to
diseases,
grew
faster
and
larger,
and
flourished
in
water
of
different
salinities and temperatures. In addition, the cultivated oysters tasted better!

饲养牡蛎

过去人们饲养牡蛎的方式很大程度上类似于田地里的农夫种植蕃 茄
--
通过移植来饲养它们。

首先，农夫选好牡蛎苗床，清除底部的旧壳和 其它杂物，然后四处撒播干净的壳。接着，他
们

栽种

已受精的牡蛎卵 。这些卵在
2
～
3
周内会孵化成幼贝。

幼贝一直漂流直到 粘在苗床底部干净的壳上为止。它们会呆在那儿并逐渐长成小牡蛎。我们
称之为种子或贝

苗。贝苗吸进海水中的微小生物作为食物从而越长越大。不久之后，农夫将这些小牡蛎收
集起来，把它们移种进其他的水域加快其生长，然后再次将它们移种进另外的水域以使其肥
壮起来。 直到最近，野生的以及人工饲养的牡蛎完全能够满足人们的需要。

但是今天这种可口的海味已 不再大量存在。这个问题已经变得如此严重以至于一些牡蛎苗床
已完全消失。幸运的是，早在
2 0
世纪初期海洋生物学家们就意识到如果不采取新的措施，牡蛎将会灭绝或至少会变为一种奢
侈的食品。因此他们建造了装备良好的孵卵场所并开始工作。但是他

们尚没有适当的装置或技 术来处理牡蛎卵。他们不知道何时、用什么以及如何喂养幼贝。他
们对捕食数百万幼小牡蛎的动物天敌也 所知无几。

他们失败了，但他们顽强地坚持了下来。终于，在
20
世纪40
年代，一个重要的突破性的进
展产生了。海洋生物学家发现，升高水

温能够诱导牡蛎不仅在夏季也在秋季、冬季和春季里产卵。后来他们发展了一项技术来喂养
幼贝至其长 成贝苗。

他们进一步成功地培养出了新的品种，可以抵抗疾病、长得更快、更大并且在不同的 盐度和
温度的水中都能茁壮生长。此外，这些培殖出的牡蛎口感更佳
!

?
????
新东方优美背诵短文
50
篇
Unit33:Plankton
浮游生物

33 Plankton
浮游生物
.
Scattered through the seas of the world are billions of tons of small plants and
animals
called
plankton.
Most
of
these
plants
and
animals
are
too
small
for
the
human
eye to see. They drift about lazily with the currents, providing a basic food for
many larger animals.
Plankton has been described as the equivalent of the grasses that grow on the dry
land
continents,
and
the
comparison
is
an
appropriate
one.
In
potential
food
value,
however,
plankton
far
outweighs
that
of
the
land
grasses.
One
scientist
has
estimated
that
while
grasses
of
the
world
produce
about
49
billion
tons
of
valuable
carbohydrates each year, the sea
’
s plankton generates more than twice as much.
Despite its enormous food potential, little effect was made until recently to farm
plankton
as
we
farm
grasses
on
land.
Now
marine
scientists
have
at
last
begun
to
study
this possibility, especially as the sea
’
s resources loom even more important as a
means of feeding an expanding world population.
No
one
yet
has
seriously
suggested
that
“
plankton-burgers
”
may
soon
become
popular
around
the
world.
As
a
possible
farmed
supplementary
food
source,
however,
plankton
is gaining considerable interest among marine scientists.
One type of plankton that seems to have great harvest possibilities is a tiny
shrimp-like
creature
called
krill.
Growing
to
two
or
three
inches
long,
krill
provides
the
major
food
for
the
great
blue
whale,
the
largest
animal
to
ever
inhabit
the
Earth.
Realizing that this whale may grow to 100 feet and weigh 150 tons at maturity, it
is not surprising that each one devours more than one ton of krill daily.

浮游生物数十亿吨的被称为

浮游生物

的小动物、植物散布在世界的海洋中。这些小的动、
植物大 多太小而难以被人眼看到。

它们随波逐流，为许多较大的动物提供了基本的食物。浮游生物曾 被描述为生长在大陆陆地
上的各种草类的海洋对应物。这种比喻是恰当

的。然而就潜 在的食物价值而言，浮游生物远胜于草类。一位科学家曾经估计，世界上的草
类每年生产大约
4 90
亿吨有用的碳水化合物，而海洋里的浮游生物每年生产的碳水化合物多于此数的两倍。尽管
浮游生物具备巨大的食物潜能，但直到最近人们还很少象种植草类

那样付出努力养殖浮游生 物。现在，海洋科学家们至少已开始研究这种可能性。全球人口不
断扩张，海洋资源作为食品的重要性日 益突出。

现在还没有人认真说过

浮游生物汉堡

会很快在世 界上流行起来。然而，作为一种可能养殖
的补充性食物资源，浮游生物正引起了海洋科学家们相当大的兴 趣。

一种似乎具有很大收获可能性的微小的虾状浮游生物被称为鳞虾。
鳞虾长至2
～
3
英寸长时即
成为地球上曾居住过的最大动物
--
蓝鲸的主要食物。成

熟的蓝鲸可以达到
100
英尺长，
150吨重，所以每头鲸每天吞食
1
吨多的鳞虾一点也不让人
吃惊。


?
新东方优美背诵短文
50
篇
Unit32:Botany
32 Botany
Botany, the study of plants, occupies a peculiar position in the history of human
knowledge.
For
many
thousands
of
years
it
was
the
one
field
of
awareness
about
which
humans
had
anything
more
than
the
vaguest
of
insights.
It
is
impossible
to
know
today
just what our Stone Age ancestors knew about plants, but form what we can observe
of
pre-industrial
societies
that
still
exist
a
detailed
learning
of
plants
and
their
properties must be extremely ancient. This is logical. Plants are the basis of the
food pyramid for all living things even for other plants. They have always been
enormously
important
to
the
welfare
of
people
not
only
for
food,
but
also
for
clothing,
weapons, tools, dyes, medicines, shelter, and a great many other purposes. Tribes
living
today
in
the
jungles
of
the
Amazon
recognize
literally
hundreds
of
plants
and
know many properties of each. To them, botany, as such, has no name and is probably
not even recognized as a special branch of
“
knowledge
”
at all.
Unfortunately,
the
more
industrialized
we
become
the
farther
away
we
move
from
direct
contact
with
plants,
and
the
less
distinct
our
knowledge
of
botany
grows.
Yet
everyone
comes
unconsciously
on
an
amazing
amount
of
botanical
knowledge,
and
few
people
will
fail
to
recognize
a
rose,
an
apple,
or
an
orchid.
When
our
Neolithic
ancestors,
living
in the Middle East about 10,000 years ago, discovered that certain grasses could
be
harvested and their seeds planted for richer yields the next
season
the
first great
step
in
a
new
association
of
plants
and
humans
was
taken.
Grains
were
discovered
and
from them flowed the marvel of agriculture: cultivated crops. From then on, humans
would
increasingly
take
their
living
from
the
controlled
production
of
a
few
plants,
rather than getting a little here and a little there from many varieties that grew
wild- and the accumulated knowledge of tens
of thousands
of years of experience and
intimacy with plants in the wild would begin to fade away.

植物学

植物学，即对植物的研究，在人类 知识的历史中占据了特殊的地位。这是人类几千年来超越
模糊的认知而真正有所了解的领域之一。

我们今天不可能知道新石器时代的祖先们对植物到底了解多少，但我们在至今仍存在的前工
业化社会观察到：人类对植物及其特性的详细了解应该是非常古老的。

这是理所当然的。植物 是其他生物甚至其他植物食物金字塔的基础。它们对人们的生活至关
重要，不仅在食物上，而且在衣物、 武器、工具、染料、

药物、住所和许许多多其他的用途上。至今仍生活在亚马逊河丛林中的部 落确实能够辨识几
百种植物并知道每一种的许多特性。

对他们来说，植物学没有专门 的名称，甚至可能根本未被认为是一种专门知识。不幸的是，
工业化的程度越高，我们距直接与植物接触 就越

远，我们的植物学知识的增加也就越微不足道。然而每个人在不知不觉中拥有大量的植物 学
知识，很少有人认不出玫瑰、苹果或兰花。

大约一万年前居住在中东的新时代的祖 先们发现某些草能被收获，它们的种子下一季耕种会
收获更多时，人类就迈出了人和植物之间的新关系第 一大步。

谷子被发现后，农业的奇迹从此诞生：这就是可栽培的谷物。从那时起，人类越来越 依赖少
数可控制的作物生存，而不再是从众多的野生种类中这里获取一点，那里

获取 一点。
这样在千万年中对于野生植物的经验和密切联系中积累起来的知识就开始消失了。


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????
新东方优美背诵短文
50
篇
Unit31:British Columbia
31 British Columbia
British
Columbia
is
the
third
largest
Canadian
provinces,
both
in
area
and
population.
It is nearly 1.5 times as large as Texas, and extends 800 miles(1,280km) north from
the United States border. It includes Canada
’
s entire west coast and the islands
just off the coast.
Most of British Columbia is mountainous, with long rugged ranges running north and
south. Even the coastal islands are the remains of a mountain range that existed
thousands of years ago. During the last Ice Age, this range was scoured by glaciers
until most of it was beneath the sea. Its peaks now show as islands scattered along
the coast.
The
southwestern
coastal
region
has
a
humid
mild
marine
climate.
Sea
winds
that
blow
inland from the west are? warmed by a current of warm water that flows through the?
Pacific Ocean. As a result, winter temperatures average above freezing and summers
are mild. These warm western winds also carry moisture from the ocean.
Inland from the coast, the winds from the Pacific meet the mountain barriers of the
coastal ranges and? the Rocky Mountains. As they rise to cross the mountains, the
winds are cooled, and their moisture begins to fall as rain. On some of the western
slopes almost 200 inches (500cm) of rain fall each year.
More than half of British Columbia is heavily forested. On mountain slopes that
receive
plentiful
rainfall,
huge
Douglas
firs
rise
in
towering
columns.
These
forest
giants
often
grow
to
be
as
much
as
300
feet(90m)
tall,
with
diameters
up
to
10
feet(3m).
More lumber is produced from these trees than from any other kind of tree in North
America.
Hemlock,
red
cedar,
and
balsam
fir
are
among
the
other
trees
found
in
British
Columbia.

英属哥伦比亚

英属哥伦比亚是加拿大的第三大省，
无论是面积还是人口都是 如此。
它几乎是德克萨斯的
1.5
倍，从美国边境一直向北延伸了
800英里
(1
，
280
公里
)
。
它包括了加拿大 整个西海岸及附近岛屿。
大部分英属哥伦比亚多山峦。
绵长而粗犷的
山脉贯通南北。甚 至那些

沿海的岛屿都是那些存在于千万年前的山脉的遗迹。在上一个冰河时期，这些山脉被冰 河冲
刷侵蚀，直到大部分山脉被淹没在海中。

它们的峰顶显现为沿着海岸散布的岛屿 。西南海岸地区有着潮湿温和的海洋性气候。从太平
洋来的温暖的洋流使得从西吹过内陆的海风变得温暖 。

因此这儿冬天平均气温在零上而且夏天也不会酷热。这些温暖的西风同样也从海洋带来了湿
气。

来自太平洋的、从海岸向内陆的风遇到海岸山脉和落基山脉这些山脉屏障。当气 流升高跨越
这些山脉时，风的温度就降低了，风中的水分形成降雨。在一些朝西

山坡 区域每年大约有
200
英寸
(500
厘米
)
的降水。大部分 英属哥伦比亚密布着森林。在有充
足降水的斜坡，巨大的道格拉斯枞树高耸入云。

这 些森林巨人常常长到高达
300
英尺
(90
米
)
，
直径粗达
10
英尺
(3
米
)
。
这些树产出了比北美
其他任何树都多的木材。铁杉、红香

椿、香脂冷杉枞都是发现于英属哥伦比亚的其它树种。

新东方优美背诵短文
50
篇
Unit30:The origin of Refrigerators
30 The origin of Refrigerators
By
the
mid-nineteenth
century,
the
term
“
icebox
”
had
entered
the
American
language,
but
ice
was
still
only
beginning
to
affect
the
diet
of
ordinary
citizens
in
the
United
States.
The
ice
trade
grew
with
the
growth
of
cities.
Ice
was
used
in
hotels,
taverns,
and hospitals, and by some forward-looking city dealers in fresh meat, fresh fish,
and butter. After the Civil War( 1861-1865),as ice was used to refrigerate freight
cars, it also came into household use. Even before 1880,half of the ice sold in New
York,
Philadelphia,
and
Baltimore,
and
one-third
of
that
sold
in
Boston
and
Chicago,
went
to
families
for
their
own
use.
This
had
become
possible
because
a
new
household
convenience,
the
icebox,
a
precursor
of
the
modern
refrigerator,
had
been
invented.
Making an efficient icebox was not as easy as we might now suppose. In the early
nineteenth century, the knowledge of the physics of heat, which was essential to a
science of refrigeration, was rudimentary. The commonsense notion that the best
icebox was one that prevented the ice from melting was of course mistaken, for it
was the melting of the ice that performed the cooling. Nevertheless, early efforts
to economize ice included wrapping up the ice in blankets, which kept the ice from
doing
its
job.
Not
until
near
the
end
of
the
nineteenth
century
did
inventors
achieve
the delicate balance of insulation and circulation needed for an efficient icebox.
But as early as 1803, and ingenious Maryland farmer, Thomas Moore, had been on the
right track. He owned a farm about twenty miles outside the city of Washington, for
which
the
village
of
Georgetown
was
the
market
center.
When
he
used
an
icebox
of
his
own design to transport his butter to market, he found that customers? would pass
up the rapidly melting stuff in the tubs of his competitors to pay a premium price
for
his
butter,
still
fresh
and
hard
in
neat,
one-pound
bricks.
One
advantage
of
his
icebox, Moore explained, was that farmers would no longer have to travel to market
at night in order to keep their produce cool.

冰箱的由来

直到
1 9
世纪中期，

冰箱

这个名词才进入了美国语言，
但冰仅仅只 是开始影响美国普通市民
的饮食。冰的买卖随着城市的发展而发展。

冰被用在旅馆、 酒馆、医院以及被一些有眼光的城市商人用于肉、鱼和黄油的保鲜。内战
(1861-1865)
之后，冰被用于冷藏货车，同时也进入了民用。

甚至在
1880
年前，半数在纽约、费城和巴尔的摩销售的冰，三分之一
< br>在波士顿和芝加哥销售的冰进入家庭使用，因为一种新的家庭设备，冰箱，即现代冰箱的前
身，被 发明了。制造一台有效率的冰箱不像我们想象的那么简单。

19
世纪早期，
关于对冷藏科学至关重要的热物理知识是很浅陋的。
认为最好的冰箱应该防止
冰的融化这样一个

普遍的观点显然是错误的，因为正是冰的融化起了制冷作用。早期为节省冰的努力，包括用< br>毯子把冰包起来，使得冰不能发挥它的作用。直到近
19
世纪末，发明家们才成功地找 到有效率的冰箱所需要的精确的隔热和循环的精确平衡。但早
在
1803
年，一位有发 明天才的

马里兰农场主，托马斯
?
莫尔，找到了正确方法。他拥有一个农场 ，离华盛顿约
20
英里，那
里的乔治镇村庄是集市中心。

当他用自 己设计的冰箱运送黄油去市场时，他发现顾客们会走过装在竞争者桶里那些迅速融
化的黄油而给他比市价 更高的价格买他仍然新鲜坚硬，整

齐地切成一磅一块的黄油。莫尔说他的冰箱的一个好处是使 得农民们不必在夜里上路去市场
以保持他们产品的低温。


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????
新东方优美背诵短文
50
篇
Unit29:Telecommuting