[化] 环烯烃

发表于:2018-12-02 / 阅读(216) / 评论(0) 分类 英语口语1+1

A hundred years ago, there are one and a half billion people on earth. Now, over six billion crowd our fragile planet. But even so, there are still places barely touched by humanity. This series will take you to the last wildernesses and show you the

发表于:2018-12-03 / 阅读(135) / 评论(0) 分类 探索与发现2012年

The penguins stay when all other creatures have fled because each guards a treasurea single egg rested on the top of its feet and kept warm beneath the downy bulge of its stomach. There is no food and no water for them. And they will not see the sun

发表于:2018-12-27 / 阅读(139) / 评论(0) 分类 探索与发现2012年

Cloze: Stingers of the Sea 海中刺客 ── 水母 Given impressive-sounding names like Portuguese man-of-war, jellyfish are certainly respected and feared by humans. Not exactly a fish, and lacking a spine, this creature has a single body cavity

发表于:2019-01-02 / 阅读(164) / 评论(0) 分类 双语有声阅读

By Jim Teeple Ramallah 23 January 2006 Politicians in the Palestinian territories wrapped up final day of campaigning Monday, ahead of crucial vote Wednesday to elect new legislature Politicians in th

发表于:2019-01-13 / 阅读(249) / 评论(0) 分类 2006年VOA标准英语(一月)

Oum Sok began working as a cyclo driver when he was 18. He says the city has become very expensive over the years, making it much harder to earn a living. New York has its yellow cab. London has its red bus. But Phnom Penh has its cyclo - a three-whe

发表于:2019-01-13 / 阅读(207) / 评论(0) 分类 VOA标准英语2010年(六)月

The State Department said Thursday an agreement for the start of direct peace talks between Israel and the Palestinians is close to completion. The deal will apparently be sealed by statements from the United States and the International Middle East

发表于:2019-01-13 / 阅读(154) / 评论(0) 分类 VOA标准英语2010年(八)月

A: Sorry to bother you, but I was wondering if you could drive me to the emergency room. B: Of course. What is the problem? A: I am running a really high fever of 105 degrees, and I have a rash on my stomach. B: If you can, go and unlock the back doo

发表于:2019-01-15 / 阅读(144) / 评论(0) 分类 英语情景对话-健康

They are constantly on the move. New-born calves have to be up and running the day they are born. But the vast herds do not travel alone. Wolves. Packs of them, eight to ten strong, shadow the migration. And they are hungry. Its the newly born calves

发表于:2019-01-23 / 阅读(160) / 评论(0) 分类 探索与发现2012年

But they are hungry and eager to reach their mother whos delayed feeding them on this special day. Now she lures them with the promise of milk, the only food the cubs have known since they were born, deaf and blind beneath the snow some two months ag

发表于:2019-01-23 / 阅读(162) / 评论(0) 分类 探索与发现2012年

Day 10. And the mother has let her cubs a mile from the den. Its time to put them to the test. Theyve grown enormously in confidence, but they dont have their mothers sense of urgency. At last it seems that they are ready for their journey. And they

发表于:2019-01-23 / 阅读(143) / 评论(0) 分类 探索与发现2012年

Midsummer on the tundra and the sun does not set. At these altitudes, the suns rays are glancing and not enough of their energy reaches the ground to enable trees to grow. Youll need to travel five hundred miles south from here before that is possibl

发表于:2019-01-23 / 阅读(138) / 评论(0) 分类 探索与发现2012年

As we travel south, so the suns influence grows stronger. And at 50 degrees of latitude, a radical transformation begins. Summers here are long enough for broadleaf trees to replace conifers. Broadleaves are easier to eat and digest, so now animals c

发表于:2019-01-23 / 阅读(160) / 评论(0) 分类 探索与发现2012年

The advance of the seasons brings constant change. As the suns influence diminishes in the north, so the deciduous forests of America begin to shut down, losing their leaves in preparation for the dark, cold months ahead. One season hands over to ano

发表于:2019-01-23 / 阅读(147) / 评论(0) 分类 探索与发现2012年

The character of the forest changes as we descend, becoming ever darker and damper, favoring different kinds of animals and plants. Less than two percent of the sunlight reaches the floor. But even here there is extraordinary variety. In the Great Is

发表于:2019-01-23 / 阅读(133) / 评论(0) 分类 探索与发现2012年

The sun beating down on tropical waters powers the weather systems of the globe. Moisture evaporates from the warming ocean and rises to create great storms. The winds generated out at sea sweep inland across the continents. As they travel across the

发表于:2019-01-23 / 阅读(158) / 评论(0) 分类 探索与发现2012年

Deer are frequent casulties of the harsh winter. And these leopards are not above scavenging from a corpse. African leopards could never survive here. But the Russian cats have thick fur to shied them from the cold. There are only 40 Amur leopards le

发表于:2019-01-23 / 阅读(171) / 评论(0) 分类 探索与发现2012年

Their secret is teamwork. Impala are their favourite prey. They start to hunt and the pack splits up. An aerial viewpoint gives a new insight into their strategy. As the dogs approach their prey, they peel off to take up separate positions around the

发表于:2019-01-23 / 阅读(150) / 评论(0) 分类 探索与发现2012年

The dogs know their prey must come out or drown. Now its a waiting game. The rest of the pack are calling. Theyve made a kill in the forest and this is an invitation to join in the meal. The impala is in luck. A pack this size kills once a day and ev

发表于:2019-01-23 / 阅读(153) / 评论(0) 分类 探索与发现2012年

All across southern Africa, all animals are journeying for the same reason. Buffalo join the great track. Nowhere else on Earth are so many animals on the move for the same urgent purpose. They are all heading for the swamps of the Okavango, a vast i

发表于:2019-01-23 / 阅读(163) / 评论(0) 分类 探索与发现2012年
学英语单词
acalyculate
ACS
alpha helix
Americanises
annihilation gamma
anomalous magma types
apara
archaeocyte
audio response system
automatic continuous function generator
basin of attractor
biotin-avidin system
birmingham standard wire gauge
boahen
board with
bow jet rudder
brolettoes
bull's-eye window
byp.
caboge
calm the liver and extinguish wind
capsful
Cholera-exanthema
concussation
convergence test pattern
cushion ring
dead-balls
dehepatized
deworming
dip coast
down cellar
eckley
first-daier
FNSIM
freewill
general average contribution
general learning ability test
glass footed stem mold
goldenrails
greensword
ground-to-ship
guaranteed wage plan
improves up on
incuse
intensity-duration
intrenching tool
irrumates
isomorphic group
kinematical equation
Kolubara
leading electrode
lingos
local service carrier
merrymeeting
micromycete
missed command probability
mustard nitrogen
Neufelden
neurological disorder
neutron curtain
normalized mass spectrum
object evidence
OMDB
orderer
overall group
oxaloacetate pathway
pantalgia
perishable inventory
photosynthetic tissue
primitive neuroectodermal tumor
pulling apart
pulsating welder
put effort into something
R-C integrating network
reduced-NAD
romjek
rural traffic survey
saxsophone
scholarly education
self-supervisory
separation factors
sickle-type embryotome
snv
spermatogenic value
sponging flour
stagger tuned amplification
staphylococcus
steam-box
sulphoxide
swotred
tapered grizzly bar
technology roadmap
Thomson Mts.
traffic link
traumatic urethral fistula
trequel
turn performance
unabstract
underglaze blue
uniparental homozygote
wrong-track
xerophorbium