时间:2018-12-30 作者:英语课 分类:托福听力短文


英语课
(woman) To us, the environment in which fish dwell often seems cold, dark, and mysterious. But there are advantages to living in water, and they have played an important role in making fish what they are. One is that water isn't subject to sudden temperature changes. Therefore it makes an excellent habitat for a cold-blooded animal. Another advantage is the water's ability to easily support body weight. Protoplasm has approximately the same density 1 as water, so a fish in water is almost weightless. This "weightlessness" in turn means two things: One, a fish can get along with a light weight and simple bone structure, and two, limitations to a fish's size are practically removed.

Yet there is one basic difficulty to living in water --- the fact that it's incompressible. For a fish to move through water, it must actually shove it aside. Most can do this by wiggling back and forth 2 in snakelike motion. The fish pushes water aside by the forward motion of its head, and with the curve of its body and its flexible tail. Next, the water flows back along the fish's narrowing sides, closing in at the tail, and helping 3 the fish propel itself forward.

The fact that water is incompressible has literally 4 shaped the development of fish. A flat and angular shape can be moved through water only with difficulty. And for this reason, fish have a basic shape that is beautifully adapted to deal with this peculiarity 5.


n.密集,密度,浓度
  • The population density of that country is 685 per square mile.那个国家的人口密度为每平方英里685人。
  • The region has a very high population density.该地区的人口密度很高。
adv.向前;向外,往外
  • The wind moved the trees gently back and forth.风吹得树轻轻地来回摇晃。
  • He gave forth a series of works in rapid succession.他很快连续发表了一系列的作品。
n.食物的一份&adj.帮助人的,辅助的
  • The poor children regularly pony up for a second helping of my hamburger. 那些可怜的孩子们总是要求我把我的汉堡包再给他们一份。
  • By doing this, they may at times be helping to restore competition. 这样一来, 他在某些时候,有助于竞争的加强。
adv.照字面意义,逐字地;确实
  • He translated the passage literally.他逐字逐句地翻译这段文字。
  • Sometimes she would not sit down till she was literally faint.有时候,她不走到真正要昏厥了,决不肯坐下来。
n.独特性,特色;特殊的东西;怪癖
  • Each country has its own peculiarity.每个国家都有自己的独特之处。
  • The peculiarity of this shop is its day and nigth service.这家商店的特点是昼夜服务。
学英语单词
acetabutar
adjustable skid
Advanced Video Codec
aerial ping pong
antepone
antiauxin
arch spring fastening
arhythmicality
at the desk
attenuation spectral dependency
auspicatory
Begicheva, Gryada
blind-spot
budgetary management
by the mark
Bārān, Kūh-e
cathetometer
cloacal pore
codswallop
cog-wheel pump
compensated carburetor
compromising reactions
conterminal
continuous voltage-rise test
contorted fissure
cooperativist
creeping junipers
cumulative damage
cut it short
data missing
dcl server image
detracin
digeridoos
dispatch box
doeings
double walled tank
drive rod assembly
efficiency bar
eigenenergies
elementary cost accounting
enrockments
erection bay
FPR
gear lapping with corudum
high temperature workshop
hits it off
hoodla
housestead
inculpative
inquiry answer
ionospheric scatter communication
Khuzhir
kilkullen
knot screen
kutteable
laak
last forever
low-loader
low-speed pulverizer
lyophilizates
m. plantaris
marmits
modular design method
National Defense Reserve Fleet
nitroquinaldine
nonisomorphically
open-loop gain characteristic
paleoseismicity
peaked curve
penile tuberculide
ponchoun
precipitationpeptization
quasirelativistic
quenching frequency oscillation
race-riot
ran away with
rip saw
river diversion arrangement
self-indication
sit at the feet of sb
skywayman
smoothy
soil anti-scouribility
sooth to to speak
specky
stitched-together
super-conductivity
suspended type of furnace
teched
the royal mail
to the consignation of
trypesis
under-cars
Uniform Rules for Collections
Upper Yarra Res.
vaiden
voltage regulators
well-rehearsed
win the wooden spoon
yuu
zero-kill