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
adjustable spanner
aminoketone
arber press
arteriae thoraciea lateralis
assembly language instruction
babassu kernel oil
bagladies
begots
berlekamp aigorithm
bilge pump suction pipe
Bougaa
capital outlay
carcass dressing percentage
carky
centi-stoke
children with special needs
chloros
closing resistor of circuit-breaker
comb nephoscope
conphaseolin
creamy chromium plating
cup-conveyer feed mechanism
cyanidin-chloride
debtor ledger
deck log voyage
dedicated team
Delacurarine
dixels
do the inside outside edge
earic
enter for
escapeproof
Eucalyptus melliodora
fall into line
faron
fifers
Folsom complex
Francois Mitterrand
fritted glassware
functions in competition
genus edaphosauruss
geologic timescales
GovNet
green ashes
Ha Long
HVDC transmission substation
jaws of vise
keep after
keyworkers
Koluton
Kuopion Lääni
land trust
leisure science
load accumulator
local batch processing
longtitudinal
luctation
luser
Mbangala
myersina filifer
objures
on probation
on site mixer
one can't hold two watermelons in one hand
out of patience
packaging material
panorpa taiheisanensis
peptics
pericardial branch
polyvinylsiloxanes
pork barrel
prenotary
proxan
pseudocercospora formosana mista
pummelings
pyrichrolite (phyrostilpnite)
Radeberg
railway network
reducing enzyme
replacement silencer
retained earnings
rock debris (rock waste)
scumble
sequential starting of switches
Serociclina
settling centrifuge
smell-smock
straight-through boiler
subsaltatory
subsidence rate
Ternstroemia yunnanensis
thermopathology
three-roll unbender
trial balance of subsidiary ledger
turbedimetric analysis
unicolored
urethral sinus
Ust'-Kan
VVF
walk with faltering pace
water control
wire television