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
abia de la obispalia
absonant
alleles
ballast branch pipe
Bender sweetening
bretheling
carnivore ecology
centralizing
cerebroside
Chase City
Cherpessa
cluster bins
collinear relationship
convergent plate boundary
Crigler-Najjar disease
crouch maneuver
ddgs
delusion of being metamorphosed
dilution and concentration test
dispatching section
disposal by sea
down-bows
echo image
effective picture signal
electrical conductivity particle counter
equivocado
extreme deformation
facies mediastinalis
fluoresecent radiation
Forest Brother
get to the road
glad-wrap
gut-shot
hand me down
holoorogenic phase
hydraulic sprinkler
immersion of thermometor
inverse tanh transformation
jewel-cases
kadeer
Kaya-gun
kumba
LECAM-1
long-fed cattle
lower derivate
Lung-shan
make-up heat
mariage blanc
Mcm
metal mold interface
militations
Minas Novas
minimizing method
month cam
morphinomane
mouse-dun
multichannel HF communication equipment
non-segregationalloy
on ... person
on-line plotter
on-off frequency
osorios
PAC
pamature
panicolid type
passage bus
perikrone
philbertia ramsayi
price leader
putao
quench texture
query name
qwq
radiotelegraph auto-alarm
Ramena
rated output of gas turbine
Razin-Tsytovitch effect
regenerative feed water heater
Right Bank
Salvia chinensis
schwarzlose
scuffs
semi-logarithmic
sequential allocation
set method
shunt-field loss
siocarbazone
sirio
social adaptation
stalo (stable local oscillator)
stationary appliance
subalitiber gun
subspecialises
television diplomacy
the shadow cabinet
totalisms
transvolations
unlawful competition
void defect
wdpa
wince
written interrogatories