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


英语课

   Create Your Own Moon Craters 2!


 
  What makes science really fun is when you get to do things yourself, so today we’re going to be making moon craters.
 
  They’re the roundish blast-marks left on the moon’s surface by ancient meteorites 4. The moon’s surface is covered with literally 5 billions of impact craters, and some of them are bigger than a fair-sized city on earth. You can see the bigger ones just with the naked eye, and with a pair of binoculars 6 you can make out many more.
 
  So now let’s make some of our own. Take a wide, flat pan, such as the kind you’d bake cookies in. Take it outside, because this gets kind of messy! Poor flour or baking soda 7 or sand across the bottom so it makes a thick, flat surface. That’s your undisturbed moon.
 
  Now have a young person drop rocks onto the moonscape. When it hits, the energy of the falling rock is transferred to the powdery surface, and voila! Impact crater 1. Instead of just doing it at random 8, though, have your young person drop one rock from a height of two feet, another from four feet, and another from six feet. You’ll find that the craters change shape depending on the energy of the incoming meteorite 3. Higher-energy impacts make wider craters, with debris 9 shooting out from their centers in what are called “rays.” Smaller ones look like little volcanoes. Throwing a stone at an angle makes an oblong crater.
 
  Afterward 10, take a look at the moon again through binoculars when it rises. You may have a better sense of what all those pock-marks really are!

n.火山口,弹坑
  • With a telescope you can see the huge crater of Ve-suvius.用望远镜你能看到巨大的维苏威火山口。
  • They came to the lip of a dead crater.他们来到了一个死火山口。
n.火山口( crater的名词复数 );弹坑等
  • Small meteorites have left impact craters all over the planet's surface. 这个行星的表面布满了小块陨石留下的撞击坑。 来自《简明英汉词典》
  • The battlefield was full of craters made by exploding shells. 战场上布满弹坑。 来自《现代英汉综合大词典》
n.陨石;流星
  • The meteorite in Jilin Exhibition Hall is believed to be the largest in the world.吉林展览馆的陨石被认为是世界上最大的。
  • The famous Murchison meteorite smashed into the Australian ground in 1969.1969年著名的默奇森陨石轰然坠落在澳大利亚。
n.陨星( meteorite的名词复数 )
  • Small meteorites have left impact craters all over the planet's surface. 这个行星的表面布满了小块陨石留下的撞击坑。 来自《简明英汉词典》
  • One theory about the existence of extraterrestrial life rests on the presence of carbon compounds in meteorites. 地球外存在生命的理论是基于陨星上存在碳化合物质这一事实的。 来自《简明英汉词典》
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.双筒望远镜
  • He watched the play through his binoculars.他用双筒望远镜看戏。
  • If I had binoculars,I could see that comet clearly.如果我有望远镜,我就可以清楚地看见那颗彗星。
n.苏打水;汽水
  • She doesn't enjoy drinking chocolate soda.她不喜欢喝巧克力汽水。
  • I will freshen your drink with more soda and ice cubes.我给你的饮料重加一些苏打水和冰块。
adj.随机的;任意的;n.偶然的(或随便的)行动
  • The list is arranged in a random order.名单排列不分先后。
  • On random inspection the meat was found to be bad.经抽查,发现肉变质了。
n.瓦砾堆,废墟,碎片
  • After the bombing there was a lot of debris everywhere.轰炸之后到处瓦砾成堆。
  • Bacteria sticks to food debris in the teeth,causing decay.细菌附着在牙缝中的食物残渣上,导致蛀牙。
adv.后来;以后
  • Let's go to the theatre first and eat afterward. 让我们先去看戏,然后吃饭。
  • Afterward,the boy became a very famous artist.后来,这男孩成为一个很有名的艺术家。
学英语单词
administration program
airtight steel shell
antimagistrical
artificial average
auto-crane
barhopper
Berg,Paul
betul-
branch line of turnout
Bratan
caligusiasis
candleless
chevisances
Chinese grapefruits
cold-set ink
common left divisors
compositional disorder
compound steel
convulsive tic disease
Coombs'reagent
dihole
discourse
edcouch
elastic temper
electron beam exposure system
empty-field(empty-space)myopia
equivalence partitioning
extoolitic
figure eight fake
fixed bayonet
forstaysail
Frozen Four
genocided
gradualities
Grassau
Greek War of Independence
grid drive characteristic
have had it up to here
heel contact
high-density digital recording
inducibly
inflectional
ins and the outs
integral-control coefficient
Italian Chamber of Commerce in Great Britain
Jeffrey,Francis
jenick
kawachi (kochi)
khuri
Komatsuzaki
krullers
London, Jack
mean highest water level
medullated nerve
medullin
murderments
navigation facilities
neurochondrite
nitrogen hardening
normal air
oberkfell
oil acid free plastic gloves
oligoporus subcaesius
Penda
plain goods
pleezer
ploimate
posterior sulcus
poststernellum
pot-boiler
presencing
pseudonarcotic
pseudonymous
quier
reneyed
resultant voltage
retention time
right-brain
rolled steel wire
runningbacks
scour-remnant ridge
sea rovers
seam pipe
spray damper
sprout-cale
ST_the-earth-and-outer-space_areas-of-land-in-general
stress and strain analysis
tertiary oil recovery
the server
thionocarbamate
town-reeve
traffic direction block
trouves
uncommonly
upside down prestressing jack
uroleucinic acid
vasoactive lung peptide
vegecultural
voltage between phases
wheatfields
zimov
zizanin