[化] 接三唑; 2H-1,2,3-三唑

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(179) / 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(193) / 评论(0) 分类 探索与发现2012年

Russian Foreign Minister Sergei Lavrov says the Kremlin has noted a positive tone in the first statements made by the Obama administration on Russian and international relations. And President Dmitri Medvedev has indicated Russian willingness to coo

发表于:2019-01-06 / 阅读(211) / 评论(0) 分类 VOA标准英语2009年(二月)

By Benjamin Sand Islamabad 26 December 2006 A Pakistani soldier keeps position inside a bunker as he monitors Pakistan-Afghanistan border at Kundi Gar post (16 Dec 2006 photo) Pakistan has announced plans to fence and mine sections of its frontier w

发表于:2019-01-12 / 阅读(230) / 评论(0) 分类 2006年VOA标准英语(十二月)

Pakistanis Tire of Water, Electricity Shortages Pakistans new prime minister, Raja Pervez Ashraf, faces a struggling economy and has said he will make the delivery of electricity a priority, but the nation is tired of constant shortages of water and

发表于:2019-01-13 / 阅读(179) / 评论(0) 分类 VOA标准英语2012年(六月)

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(206) / 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(216) / 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(198) / 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(188) / 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(212) / 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(196) / 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(180) / 评论(0) 分类 探索与发现2012年

The strike of a great white shark lasts a mere second. Slowing it down forty times reveals the technique and immense strength of this massive predator. If surprise fails, there will be a chase. The shark is faster on a straight course, but it cant tu

发表于:2019-01-23 / 阅读(286) / 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(208) / 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(224) / 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(200) / 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(209) / 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(219) / 评论(0) 分类 探索与发现2012年

At the peak of the dry season in the Kalahari, water arrives in the Okavango. It fell as rain a thousand miles away in the highlands of Angola and has taken nearly five months to reach here. The water drives out insects from the parched ground which

发表于:2019-01-23 / 阅读(192) / 评论(0) 分类 探索与发现2012年

London-based Silent Opera is bringing their latest work Vixen to the ongoing Beijing Music Festival. The innovative opera is an adaptation of Czech musician Leos Janacek's original music production The Cunning Little Vixen. Changes have been made to

发表于:2019-02-14 / 阅读(287) / 评论(0) 分类 2017CRI中国国际广播电台
学英语单词
abscondee
alternate heating and cooling
atalaya
be born in
biovalves
birth policy
bobby-soxers
budding and appendaged bacterium
bullbars
butt-swell
chamber kiln
christsakes
combed cotton
corticonuclear tract
delta modulation technique
dilution limit
doubletracks
drupiferous
emperality
enwalled
exempt person
formamidine disulfide
freeboard measurement
frost over
fuel assembly insertion
general trustee
genus cortaderias
genus Taenia
gobis
golden horse awards
had advantage over
heredosyphilis
highland
hiplength
historical profit
honor one's liability
hot humid
hurrea
in-line skating
infinitesimal calculuss
interpleural furrow
is greater than
knowledge base
lay someone low
ledger analysis
lee-lone
liquor license
LSAPI
mercurous bitartrate
myoinositol monophosphate
negative modulation factor
nephashoth
nesewort
Oak Park Res.
Omar stanza
orosius
outcounted
outstood
periscope
perpendicular axis theorem
photo-sensor
pine for
plain card
plain shunt
pneumatolytic alteration
population base
postparietals
pregenital segment
presoaking
pseudopileatus
public privilege
qcom
radioactive electron capture detector
reserve-power source installing system
right of privacy
scantling draft
Schistostegiaceae
Secale sylvestre
shellside water test
shovel type excavator
single turnout
smokos
Sonvilier
ssrc
starter of fertilizer in seedbed
supercooled air
surveying logic
suspended flight conveyor
tampyne
tandem office
tepache
ternary azeotrope
too much information
truncate wing
two boat seine vessel
unit of taxation
US social security tax
variable-gain
very-close-coupled
Whitman's frame
workmindedness
YouTube download