取样层位

A: Why are you handing me a plastic cup? B: Your doctor wants to test your urine and needs a sample. A: How am I supposed to do that? B: We need you to urinate like you normally would, and then stop and finish into the cup. A: What am I supposed to d

发表于:2018-12-02 / 阅读(330) / 评论(0) 分类 英语情景对话-健康

Conditions on Mars were so harsh that it was hard to imagine any life surviving there. The idea of sophisticated aliens was wiped out. We know that conditions on Mars today are not very good for life.

发表于:2018-12-07 / 阅读(271) / 评论(0) 分类 火星生命

These discoveries raised the stakes. Here was a planet similar to our own. Mars might not have cities or civilizations. But it could be home to other smaller life forms like microbes. Chris McKay is N

发表于:2018-12-07 / 阅读(297) / 评论(0) 分类 火星生命

I think it is exciting. Because it would imply that if life arose independently on Mars. The implication is that life is pervasive throughout the universe. This is why Mars has so obsessed scientists.

发表于:2018-12-07 / 阅读(283) / 评论(0) 分类 火星生命

In 2001 a new NASA probe was launched. Called Odyssey, it was sent to Mars to carry out the most detailed analysis ever of the planet’s surface. What it has discovered may be about to answer one of

发表于:2018-12-07 / 阅读(255) / 评论(0) 分类 火星生命

But even if there had been water, life doesn't start overnight. Even a simple microbe is the product of complex chemical systems that take millions of years to evolve. Had the water lasted long enough

发表于:2018-12-07 / 阅读(269) / 评论(0) 分类 火星生命

Rice had seen the same thing in Iceland, one of the few places on Earth with similarities to Mars. It too is extremely cold, and most of the water is frozen into glaciers. And also like Mars, buried u

发表于:2018-12-07 / 阅读(315) / 评论(0) 分类 火星生命

For Mars to have rivers, it must once have had streams, rain, clouds and an atmosphere, a planet just like the Earth today-if these were rivers. They had to be sure. The answers would come in 1998 wit

发表于:2018-12-07 / 阅读(302) / 评论(0) 分类 火星生命

William Boynton is professor of planetary sciences at the University of Arizona. And he's dedicated his life to looking for water on Mars. The link between life and water is very strong. Even here in

发表于:2018-12-07 / 阅读(282) / 评论(0) 分类 火星生命

'Deepwater Horizon' Honors The Sacrifice Without Sacrificing The Action play pause stop mute unmute max volume 00:0003:02repeat repeat off Update Required To play the media you will need to either update your browser to a recent version or update you

发表于:2018-12-18 / 阅读(244) / 评论(0) 分类 2016年NPR美国国家公共电台10月

Of course, any terraforming is still a long way off. The next few expeditions to Mars will definitely be made by machines. NASA, are sending 2 rovers, capable of travelling over 100 meters a day in se

发表于:2019-01-02 / 阅读(268) / 评论(0) 分类 火星生命

Well, hearing that Odyssey had found subsurface water on Mars was enormously exciting for somebody who is involved in planning to send humans to Mars. Water has a number of important uses for us. At t

发表于:2019-01-02 / 阅读(334) / 评论(0) 分类 火星生命

Life on Earth is basically proteins and DNA, so we can wonder if there is life on Mars will also be DNA and proteins, the same type of DNA, the same type of proteins. One might think that DNA is such

发表于:2019-01-02 / 阅读(268) / 评论(0) 分类 火星生命

But there was something even better. Odyssey may not just have found ice. There may also be liquid water, and that means, there could be living creatures there too. Right now, there might be liquid wa

发表于:2019-01-02 / 阅读(325) / 评论(0) 分类 火星生命

But they never got there. The first disappeared into deep space. Another missed its target when its coordinates were confused. One NASA control center was working in metric, the other in feet and inch

发表于:2019-01-02 / 阅读(345) / 评论(0) 分类 火星生命

The ground here is permafrost, a mixture of soil and ice frozen together. A group of Russian scientists have teamed up with NASA to drill down into it in search of microorganisms. It's work that's bee

发表于:2019-01-02 / 阅读(296) / 评论(0) 分类 火星生命

One of these wavelengths corresponds to hydrogen, another wavelength would be iron. Another wavelength would be oxygen. And so you go to the part of the spectrum you are interested in and you see you'

发表于:2019-01-02 / 阅读(295) / 评论(0) 分类 火星生命

RACHEL MARTIN, HOST: Eight years ago today, an explosion on the Deepwater Horizon drilling rig killed 11 people and led to a massive oil spill in the Gulf of Mexico. The accident prompted big changes in how the country regulates offshore drilling. No

发表于:2019-01-16 / 阅读(283) / 评论(0) 分类 2018年NPR美国国家公共电台4月

Below you will find a sample outline and the essay written from that outline. OUTLINE Paragraph 1 (Introduction) I. Leading sentence: It took me eighteen years to realize what an extraordinary influence my mother has been on my life. II. Summary of m

发表于:2019-01-20 / 阅读(346) / 评论(0) 分类 实用英语

A: What is that plastic cup for? B: Your doctor has requested a urine sample. A: Am I supposed to pee into the cup? B: We want what we call a clean sample. Urinate a drop or so into the toilet, and then stop the flow and urinate into the cup. A: Then

发表于:2019-02-27 / 阅读(284) / 评论(0) 分类 健康-Health
学英语单词
abounded
adjustabletool
afro-wigs
alpha-beta pruning
ambrosin
amphipterygid
anticonvulsant
average age at marriage
balbiani ring (beermann 1952)
ball cartridges
barefacedness
batchmeter
be out of balance
beater drag
belt separator
black salsify
Brassica nigra
bug-hunters
bugno
bytaught
carked
childers
choiceful
civil aeronautics
common block analysis
consumption price index
council of military court
cuk-
deckas
diameter of equivalent circle
diaryl
dimictic
discrete valued objectives
electrochemical valence
epidithiodioxopiperazine
equipment requirement specification
faulty goods
Februarye
feel grateful
flower-like
forswearing
frictional damper
had been done
Hammer's tests
hemixis
high-explosive cargo
high-speed mixer
HVDS
Hydrangea integrifolia
intraprogram documentation
jabrils
jaw clutch
Laxova
ller
logarithm transformation
long-run loss
magmatogene rock
mechanical rock bolt
Micklehurst
molyte
multilateral frontier
munseyella oblonga
nepenth
network-network interface
Neumann's sheath
nonconfigurable
piezocaloric coefficient
pineyard
pole of a quadric surface
preferential trade arrangement
Qorveh
rail catch
reflex mirror locking lever
regular tenacity
regulating extraction steam valve
response level
salt hydrate
scheduled repairs
security protection
shallow-diffused cell
skin covering of the surface
solar radiation factor
stabilizing magnetic field
starting jet
steel low carbon
strict convexity
tarpaulin rod
thymoma
tracking spacing
transition card
two of a trade never agree
underwater probing
uniformity of temperature
ununquadium
upsends
vendor performance index
ventilation/perfusion
winning prize
wisecracked
woof yarns
yezd
zinc dust method