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
age-corrected basis
airline-industry
amylolytic enzyme
antipitching device
antre
arch springing hinge
asset management
attack in force
average yield
be emulous of
box-j
brass wire mesh
by some means
calcium lactates
capital goods policy
chalk-dusts
chamaecyparin
choi sum
continuous discrete system simulation language
cornrowing
correction of depth
council tables
coverage (insurance)
cultural cringe
cyclic heating method
deficit matrix
dhaola dhar
discoing
distyryl
duen
e-media
electro-photo luminescence
episyllogistic
Erichsen number
fading rise
favourable prognosis
fiscal compensation
fling in with
food borne disease
Formosamine
generating boat
gentiobiosyloleandrin
groth
hemicephaly
high speed connect
Innokent'yevskiy
king edward
Kocharite
matterwaves
microparticle counter
Microtraps
modem-less connection
modified zigzag test
month variation
mutual integral-differential operator
mycena haematopus
NAVMEDATASERVCEN
nervous earth
neuroceratin
nickel chloride
NITF
non-radicals
nonhysterical
normocapnic
outglittering
paleontologic instant
phosphorylethanolamine
pink toes
piupiu (maori)
plant engineering department
point designation grid
polar control system
process redundancy
ptyalose
radio rack
radioactivated
reference color
rejection of proof
reversal experiment
Rhododendron moulmainense
safety tread
sheebas
sheep grazing
sonnenfeldt
Sphaerotilus fluitaus
square shooters
startability of motor fuel
stepping stone on water surface
stub-end freight station
Svit
Symplocos glandulifera
transcontinentally
tuteloes
unified finance and credit system
Veneris mons
Vignanello
vukusic
web-footed geckos
winter-blooming
yuquilla
Zhaksykylysh, Ozero
Ziemann's stippling