时间:2019-02-24 作者:英语课 分类:英语听力文摘 English Digest


英语课

  世界上跑得最快的是什么?答案是光速。它每秒能跑186,280英里。因为即使在太空中,光速也大致相同,所以光年也就用于描述不同星球之间的距离。记住了哦,光年是距离单位,不是时间单位。同时光这么快的速度又对我们有什么意义呢?一起听听吧。

If you’re driving on an interstate highway, the only thing keeping you from going faster than the speed limit is your sense of civic 1 duty, or perhaps that police car up ahead.

There’s one speed limit, however, that most scientists agree nothing will ever break.  That’s the speed of light:186,280 miles per second.


  As it travels through deep space, light moves at exactly this speed, no more and no less.The speed of light is so reliable, we even use it to measure distances between the stars.

If it takes starlight fifty years to reach us, we say that this star is fifty light years away.

You might be surprised to learn, however, that light itself does not always travel at the speed of light.Our interstate highways generally have a higher speed limit, but once you enter a city or residential 2 street, the speed limit lowers.

Likewise 3, light travels at its maximum speed through a vacuum 4 the interstellar highway but it slows down when it enters air, water, or some other medium.

Through air, light moves a hint 5 slower:  forty miles per second less than its maximum speed.Through glass, light moves almost eighty thousand miles per second slower.

Light moves more than a hundred thousand miles per second slower through a diamond less than half its speed in a vacuum.

Light moves so quickly anyway, do we ever notice this change in speed? Actually, we do.When light slows down it also bends slightly.This is know as refraction.

Lenses 6 use the lower speed limit of light in glass to bend and focus the light.If light always moved at it’s maximum speed, none of our telescopes, eyeglasses or even our eyes themselves would ever work.



adj.城市的,都市的,市民的,公民的
  • I feel it is my civic duty to vote.我认为投票选举是我作为公民的义务。
  • The civic leaders helped to forward the project.市政府领导者协助促进工程的进展。
adj.提供住宿的;居住的;住宅的
  • The mayor inspected the residential section of the city.市长视察了该市的住宅区。
  • The residential blocks were integrated with the rest of the college.住宿区与学院其他部分结合在了一起。
adv.同样地,照样地;也,又
  • The explorers had to undergo much suffering.探险者不得不忍受很多困苦。
  • The planes have to undergo rigorous safety checks.飞机必须经过严密的安全检查。
n.真空,空间,真空吸尘器;adj.真空的,产生(利用)真空的;v.用吸尘器打扫
  • Sound waves will not travel through a vacuum.声波在真空里不能传播。
  • He sells vacuum cleaners.他经销真空吸尘器。
n.暗示,示意;[pl]建议;线索,迹象;v.暗示
  • He gave me a hint that I was being cheated.他暗示我在受人欺骗。
  • He quickly took the hint.一点他就明白了。
n.透镜,镜头( lens的名词复数 );眼睛中的水晶体
  • a pair of glasses with tinted lenses 一副有色镜片眼镜
  • Wash the lenses in saline solution. 用盐溶液清洗镜片。
学英语单词
2-methylcortisol
aceraius grandis
Aconitum refracticarpum
allantois chorioidea
aquachloral
arsecheek
avant-gardists
back-channeled
be better of
bean tree
Biankouma
body-thrusts
buarques
bwe
C-Prolog
cable distribution point
Chattertonian
claisen para-rearrangement
coati-mundi
colour screw
Crookes' lens
cumulative error
cylinder cover bolt
date of clearance
dibutyryl
Diphyllobothrium erinacei
diplosomites
dome cap
drip gasoline
drywell ambient temperature
error locating
Euro share market
exhibition space
famale worker
fineberg
flunk
foam in hibitors
foreign exchange option
furnace transformer
gross out
half-bottles
heavy lorry
heterodyne repeater
household word
immanacled
income tax authority
intermodal freight terminal
johann maier ecks
josher
khanaqin
Kundsen-langmuir equation
Kutta-Joukowski airfoil
line broadening
linearly equivalence
lorente
lump salt
mating plug
melomelus
Middeldorpf's triangle
near-optimality
neurogenin
non-parametric cointegration
non-provisional
normal atmosphere
nucleus of the solitary tract
nurserygirl
Odawara
orbitosphenoids
Oto-Manguean
owner-like
phase contour
pig pile
plocamium telfairiae
Plutonian
positive vector
pressure-feed oiling
pullulatings
rabbet line
residual noise
reverse intergenerational influence
rodder
sael
sales record
sayan
scrambly
Silicon Wadi
single-action pressing
spongy brake pedal
structural basis
submolecule
sunk-in
Talodex
test harnesses
thunder thighs
torcious
transition state,transition complex
trimmed in bunker
unaccused
unbenzoled petrol
white mahogany
whitenest
zoocoenology