氧碳原子比

CHAPTER TWO Reading POLLUTUO FIGHTERS [00:09.90]Judy is collecting some facts for a class project on pollution. [00:18.44]She is interviewing Doctor Ray,a scientist,about trees. [00:27.51]Judy:Why are you so interested in trees,Doctor Ray? [00:38.16]

发表于:2018-12-01 / 阅读(482) / 评论(0) 分类 上海牛津初中英语八年级

.....green plants ultimately. When it first appeared therefore, it would have been seen as a poison, it would have been a pollutant. But gradually, through Darwinian natural selection, living organism

发表于:2018-12-07 / 阅读(132) / 评论(0) 分类 寻访外星人

This is Scientific American's 60-Second Science. I'm Steve Mirsky. Got a minute? On June 4th we told you about iron snowflakes on Mercury. Today we have some radical news about the atmosphere of Venus. Literally, a radical is a molecule that reacts e

发表于:2018-12-24 / 阅读(115) / 评论(0) 分类 Scientific American(六)月

Here are two seemingly unrelated facts. One: from the late 1940s through 1963, we tested atomic bombs in the atmosphere. Two: wine lovers are sometimes duped into spending exorbitant amounts for fake vintage bottles that werent from the year they wer

发表于:2018-12-24 / 阅读(112) / 评论(0) 分类 Scientific American(三)月

Item eight. Vocabulary. fossil, molecule, hydrogen, carbon, sulfur. Petroleum has been important since ancient times. In Latin, the name means rock oil. Petroleum is a fossil fuel. The liquid comes from the remains of plants and animals that died mil

发表于:2018-12-27 / 阅读(103) / 评论(0) 分类 step by step 3000 第一册

数千年来,大气中碳12和碳14的比例是稳定不变的,然而,二十多年以来的原子弹试验,使得碳14的水平增加。生长中的葡萄吸收了空气中的二氧化碳,而通过测试葡萄中的碳含量,就可以大致

发表于:2019-01-02 / 阅读(171) / 评论(0) 分类 60秒科学

发表于:2019-01-02 / 阅读(205) / 评论(0) 分类 寻访外星人

This is Scientific Americans 60-Second Science. Im Christopher Intagliata. Got a minute? Imagine climbing diamond mountains, or hiking around the graphite shores of a lake of tar. Sound a little sci-fi? Well a new discovery suggests planets like that

发表于:2019-01-08 / 阅读(126) / 评论(0) 分类 Scientific American(十二)月

When it comes to sheer celestial bling, stars might not corner the market on twinkle, because beneath their rocky exteriors, some terrestrial planets may be half diamond. So said scientists at the fall meeting of the American Geophysical Union. The r

发表于:2019-01-08 / 阅读(144) / 评论(0) 分类 Scientific American(十二)月

This is Scientific Americans 60-Second Science. Im Karen Hopkin. This will just take a minute. If youve ever wondered where the Earth came from, the answer, it seems, is blowin in the windthe solar wind. Or so say scientists who, after examining sola

发表于:2019-01-08 / 阅读(161) / 评论(0) 分类 Scientific American(七)月

Dear Editor, I live in Paris,France.In my country there is a famous site,called the Chauvet Caves.I am very worried about it because some of the cave paintings have been destroyed by air pollution.No,the pollution does not come from cars or factories

发表于:2019-01-09 / 阅读(173) / 评论(0) 分类 高中英语听力人教版第一册

A unique program to capture carbon at coal power stations has been unveiled in Australia. Operators of a demonstration plant say it is the first of its type in the world and involves burning coal in oxygen rather than air, which reduces carbon dioxi

发表于:2019-01-13 / 阅读(143) / 评论(0) 分类 VOA标准英语2008年(十一月)

And how, you may reasonably wonder, can scientists know what oxygen levels were like hundreds of millions of years ago? 你也许有理由想知道,科学家们怎么会知道几亿年以前的氧气浓度? The answer lies in a slightly obscure b

发表于:2019-01-17 / 阅读(133) / 评论(0) 分类 万物简史

Those planets are all going to be so hot, and you cant develop something as complex as life. Scientists have gone back to the drawing board, looking to find worlds capable of supporting life, small rocky planets like earth. We dont know that life has

发表于:2019-01-22 / 阅读(116) / 评论(0) 分类 自然百科2010年

The Time Before Fire What is fire anyway? Well, fire is rapid oxidization . Its the energy released when oxygen atoms start combining with carbon and hydrogen atoms. Exactly, so without oxygen in the air, nothing burns. You mean there was a time befo

发表于:2019-01-26 / 阅读(101) / 评论(0) 分类 英语听力文摘 English Digest

German Car Manufacturer Audi Creates Fuel From Air And Water 奥迪用空气和水合成新燃料 Creating an alternative green or carbon neutral fuel to replace gasoline has been the holy grail for scientists for many years. However, while there has

发表于:2019-02-05 / 阅读(108) / 评论(0) 分类 阅读空间

Although our cell was large, we obviously had used up most of the oxygen it contained. 虽然牢房还算宽大,但很明白,我们已经消耗掉了里面大部分氧气。 In essence, over an hour's time a single human being consumes all the ox

发表于:2019-02-17 / 阅读(125) / 评论(0) 分类 《海底两万里》中英双语有声读物

台湾籍旅美老师今天交给我们的句子是: Let's look at the characteristics that make an animal a fish. Fish live in the water, and they can breathe underwater. They use gills, not lungs, to get oxygen from the water around them. 我们来

发表于:2019-03-05 / 阅读(139) / 评论(0) 分类 留美老师带你每日说英文

台湾籍旅美老师今天交给我们的句子是: Soft tissue, on the other hand, isn't as dense, and contains mostly lower atomic number elements, like carbon, hydrogen, and oxygen. So more of the X-rays penetrate tissues like lungs and muscles

发表于:2019-03-05 / 阅读(220) / 评论(0) 分类 留美老师带你每日说英文

What Is Fire? 火是物质燃烧过程中散发出光和热的现象,是能量释放的一种方式。火焰分为焰心、中焰和外焰,温度由内向外依次增高。燃烧过程必须有可燃物、燃点温度、氧化剂三项并存,缺一

发表于:2019-03-09 / 阅读(305) / 评论(0) 分类 英语听力文摘 English Digest
学英语单词
acceleration load
actual loading
address pattern
Aesfarrapa
air-producer gas
algebraic languages
all this time
AlsanateWycakon-G
antarafacial
antidemocratic
arnaout (albania)
assam rubbers
automaticsize
ba'th
balck cable
basolateral nuclues of amygdala
bechesthesia
begad
bioptix
BPHEO
brunched
capilene
Chotin
collections
crateloads
current of action
dangled
decimillimeter
delightfulnesses
diazocyanide
disodium pyrophosphate
document reproduction
earth tripolite
Elizabeth Bay
enantiomeric excess
foreseize
Frauenfeld
free worlds
galvanized flexible conduit
general surplus
genus Heracleum
grapefruit juice
hail attenuation
hereditary hypophosphatemic rickets
holmenkollen
housing action area
hypoglossal nuclei
in small amounts
interprofessional
jumbul
justicia procumbens hirsuta
Kamai
L-Ovalbumin
lalonde
laser phototypesetter
lesserite
light power meter
local on-line card reader
Macdonald, L.
mobile operating system
Monapen
more fool
necessary stool
nerve compression
non-stocks
nonsilk
OI-dash
oil floatation
OR (order register)
oriental type cigarette
overlay
parachute sublateral bands
parallegic
picket rope
pickled food
pleiophylly
potentiometer oil
printed-circuit solder plating
pulsed light diode
put on a show
Radolfzell am Bodensee
rake mixer
remediless
remou
richard nixons
run at a loss
saw teeth
SAW(submerged arc welding)
silberhornerz (chlorargyrite)
snow cave
springer
St-Aignan-sur-Roë
subminimax minimal sufficient statistic
taar
television fee
truck beds
truehearted
ventricular plateau
veol
vital statisticstechnique
wave band changing switch
wire grip