时间:2018-12-31 作者:英语课 分类:英语听力文摘 English Digest


英语课

   Why Do Zebras Have Stripes?


 
  For many animals, camouflage 1 is an important part of survival. A leopard’s spotted 2 coat and a polar bear’s white fur help them blend into their respective environments. But a zebra’s bold stripes can’t help to disguise it in its natural habitat, the open plains of Africa.or can they?
 
  Why Zebras Have Stripes? On this moment of science.
 
  The zebra’s bold markings can also help to conceal 3 it. In 1844, naturalist 4 Francis Galton pointed 5 out that stripes can help disguise zebras in the dim, grayish light of an African night. Fifty years later, an artist named Abbot Thayer suggested that stripes could help actually change the way a predator 6 sees a zebra.
 
  The zebra’s bold markings draw the viewer’s attention to the stripes themselves, not the shape of the animal. So when a predator looks at a zebra, it sees stripes first, and then the zebra. This split second of recognition gives the fleet-footed zebra a chance to escape.
 
  To other zebras in the herd 7, the flash of stripes they see when one zebra starts to flee from an approaching lion is a “follow me” signal. Like the white flash of a deer’s tail, it alerts the entire herd to danger. The approaching lion, on the other hand, often loses his initial target in the confusing mass of moving stripes.
 
  Stripes also allow young zebras in search of a meal to identify their mothers. When mating, adult zebras use stripes to recognize members of their own species.
 
  As one nineteenth century breeder discovered, a female zebra will object vehemently 9 to mating with a male ass 8. But when the rejected suitor was disguised with hand-painted stripes, the female zebra happily accepted him.

n./v.掩饰,伪装
  • The white fur of the polar bear is a natural camouflage.北极熊身上的白色的浓密软毛是一种天然的伪装。
  • The animal's markings provide effective camouflage.这种动物身上的斑纹是很有效的伪装。
adj.有斑点的,斑纹的,弄污了的
  • The milkman selected the spotted cows,from among a herd of two hundred.牛奶商从一群200头牛中选出有斑点的牛。
  • Sam's shop stocks short spotted socks.山姆的商店屯积了有斑点的短袜。
v.隐藏,隐瞒,隐蔽
  • He had to conceal his identity to escape the police.为了躲避警方,他只好隐瞒身份。
  • He could hardly conceal his joy at his departure.他几乎掩饰不住临行时的喜悦。
n.博物学家(尤指直接观察动植物者)
  • He was a printer by trade and naturalist by avocation.他从事印刷业,同时是个博物学爱好者。
  • The naturalist told us many stories about birds.博物学家给我们讲述了许多有关鸟儿的故事。
adj.尖的,直截了当的
  • He gave me a very sharp pointed pencil.他给我一支削得非常尖的铅笔。
  • She wished to show Mrs.John Dashwood by this pointed invitation to her brother.她想通过对达茨伍德夫人提出直截了当的邀请向她的哥哥表示出来。
n.捕食其它动物的动物;捕食者
  • The final part of this chapter was devoted to a brief summary of predator species.本章最后部分简要总结了食肉动物。
  • Komodo dragon is the largest living lizard and a fearsome predator.科摩多龙是目前存在的最大蜥蜴,它是一种令人恐惧的捕食性动物。
n.兽群,牧群;vt.使集中,把…赶在一起
  • She drove the herd of cattle through the wilderness.她赶着牛群穿过荒野。
  • He had no opinions of his own but simply follow the herd.他从无主见,只是人云亦云。
n.驴;傻瓜,蠢笨的人
  • He is not an ass as they make him.他不象大家猜想的那样笨。
  • An ass endures his burden but not more than his burden.驴能负重但不能超过它能力所负担的。
adv. 热烈地
  • He argued with his wife so vehemently that he talked himself hoarse. 他和妻子争论得很激烈,以致讲话的声音都嘶哑了。
  • Both women vehemently deny the charges against them. 两名妇女都激烈地否认了对她们的指控。
学英语单词
a bump in the road
act ... out
air-gap clearance
alcohol-oxidoreductase
anse
antithesistic
apply for a position
Aram Kachaturian
augustn
Batrachia
be in receipt of
be wanting
blow his own trumpet
Caprim
car loading system
carevision
cell complex
check-valve body
choice clause
chrisman
controllable area nozzle
coprotagonists
corporation excise tax
detonation limits (in air )
disione
DSH (deactivated shutdown hours)
earth stationary orbital keeping
Elassomatoidei
europium dichloride
executory agreement
faille
farley maidenhairs
Fasnakyle
floor manifold
formating
Hartley transform
hatchet man
hereditary retinoschisis
high in
hydrodynamic effect
hydroxyphenylglutamine
ideal base
Irago-zaki
jacknifed
jawad
keep one's hands in one's pockets
knee lever
koton karifi
kuni
lasiopetala
leonite
linearity test card
lubricator for slick line
luminescence of crystallization
Lundborg
mellic
migration before stack
minguss
molecular bombardment
moving top table
natural mortality
NMU
nuclear scientist
one way rolling key clutch
opel
ottowa
overlapped instruction execution
personal records
piston ring pliers
plsgiocephalic
Pochinkovskiy Rayon
primecost variance
Prosopis
quarai
quelqu'un
R.A.C.
repurchase mandate
restraint modulus
RF transform tower
rock bedding
scholte
self contained battery
senile dementia
side gear
spriocheto-
stiep
sweeet
sweetgale
system information
test function space
trislander
tube data
unhydrolyzed protein
unprobably
unreclaiming
unverity
vapor liquid equilibrium
virolysis
ward leonard system
warm-up of unit
Wu-chang
Zahrez Chergui