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
adhering salt
adiabatic-efficiency
alveolar foramina
angiotribe
angular reamer
artificial rain device
beta disintegration
black-or-white
blow-bye
breed up
CAGM
Caramel, R.
Carcroft
Chibougamau R.
Chilombo
chip carving
congeneic strains
cracking salt
cylinder-bore
cylindrical magnetic thin film memory
daniel boones
DC mains
delicate problem
door pivot
dynamical boundary value problem
Epimedium pauciflorum
Eurasian Union
extruding die
faxcasting
fluent aphasias
fountains of youth
fucking machines
Gere
Gomphrena globosa
high velocity fluid
Hoek van Holland
hoisting gin
hurt-sickle
influence-peddlers
infrared EDM instrument
ipomoea leucantha
Kazbek
Khogdo
leaching colloidal
leadhammer
London Oil Pollution Convention
Loreto
low(er) heat(ing) value
MacAlpine L.
mahatma gandhis
make out our case
maltodextrins
maximum recommended firing current
medicinal usher
medium level clouds
meteorologic dispersion
mixed paper-stock
Mn-Fe ratio
never in a month of Sundays
Nisho
non-crossing correlation rule
nonleaded (nonlead)
nonretaliatory
nuptiality rate
open-chain
oxygen-steel process
pastoral letter
persistatron
piling it on
planned growth target
porks
R-ratio
respirates
Rhododendron nanjianense
ribofuraose
richaud
rolling settlement
rubber constituent
sacche
saccular maccula
scandalled
shot putters
sounds out
sport organ physiology
state owned forest farm
supermajorities
system outage
tabular cross-tratification
task of making segment known
tomassetti
trioxytriphenylmethane
true-banked turn
unconfigured
Veraval
viewing duration
waste copper
white-handed
whorlwyl
wind-heat invading lung
with one's eyes shut
worked my ass off
zephanias