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
'Baby Face' Nelson
-laden
3-hydroxy-2-butanone
acetyl galactosamine
active source method
administrative examination
Aetosauria
ageratinas
agricultural appropriation
airwar
algorithmically
angle of traverse
Ariadnoye
assume jurisdiction over the case
back reach
basin turning coupling
beautiful people, Beautiful People
bombyciferum
BP button
budget-maximizings
buzzert
chain base
Chapultenango
clearing away heat to stop bleeding
coenozygote
commandingness
common shrimp
compressional fault
conformal cone projection
coring conventional
Cotunnius'space
cylindrical coordinate manipulator
dataplanes
disciplinary action
division in capital ratio
dormant equipment
drapetomania
drumbeater
duct papilloma
dumb as a fish
ecological surveillance
entertainment-shopping district
feel rotten
first aid treatment
friendlessnesses
functionally
galactic rotation
grant a parole to sb
hardstand parking
henipavirus
hygienise
hypengyophobia
hyphoderma microcystidium
hypocentral plot
INTELSAT system records
irish touchstone
isotropic compression
Jasminum prainii
karlo
law-related
maag
macaroni tubing
magneticness
mallove
masoods
Merpectogel
metal slitting saw
multiple tariff
Neisseria gonorrhoeae
of the year
operating environment
order entry
period depreciation charges
phototaxis,phototaxy
pickaback plant
Platz
plummet survey
postmultiplied
product assortment
project planning chart
red iron oxide
rudeness
sbl
scirrhophthalmia
septuagesimas
seven rib roast
silent person
Sinj
solubilizable
spinae
super-sizes
superacids
system administration networking and security
Thermoanaerobium
thermobalances
togarashi
total variation decreasing scheme
tug of love
weaponing
wide-coverages
wooly mammoths
wussing out