4-碘咪唑

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(120) / 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(121) / 评论(0) 分类 探索与发现2012年

AMERICAN MOSAIC -April 19, 2002: Jazz Violinist Regina Carter / Question about the Washington Monument / Museum Show on Wood Turning Broadcast: HOST: Welcome to AMERICAN MOSAIC — VOA’s radio magaz

发表于:2019-01-04 / 阅读(205) / 评论(0) 分类 American Mosaic

Azaz Residents Pick Up After Aerial Bombings The residents of Azaz clean up and mourn after Wednesday's deadly bombing by Syrian government warplanes. Azaz had been peaceful in recent months, although forces of the rebel Free Syrian Army have had to

发表于:2019-01-13 / 阅读(153) / 评论(0) 分类 VOA标准英语2012年(八月)

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(141) / 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(140) / 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(125) / 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(123) / 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(139) / 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(123) / 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(113) / 评论(0) 分类 探索与发现2012年

The female retires to consider her verdict. Its hard not to feel deflated when even your best isnt good enough. The sun influences the lives in the ocean just as it does on land. Its richest parts are those where waves and currents bring fertilizing

发表于:2019-01-23 / 阅读(146) / 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(232) / 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(126) / 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(149) / 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(116) / 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(133) / 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(137) / 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(117) / 评论(0) 分类 探索与发现2012年

By Jim Teeple Jerusalem 03 November 2006 Palestinian women march towards the northern Gaza Strip town of Beit Hanoun, Nov. 3, 2006 Two women were killed Friday and about ten others wounded after Israeli troops fired on a group of women acting as hum

发表于:2019-02-07 / 阅读(159) / 评论(0) 分类 2006年VOA标准英语(十一月)
学英语单词
2-3 tree
a twinge of conscience
administrative records
amound of work
angiotension
angle of appoach
ardiac skeleton
automatic alarm logger
award mandate
B.I.A.
be on one's legs
begettest
behavior potential
buffer species
bypass damper
caburn
calving jack
charter for carriage of goods
chimyl alcohol
Cistales
cocobean
conjointly
control of braking
dakhla oasis
decontamination system pump
density contour
divingboard
double line ground fault
double-spiral classifier
dref
Dundrearyisms
dvitellurium
elements of exterior orientation
entity subtype
European cranberrybush
expert opinion
fevertrap
fighting postion
flattereth
floating algae
foodservice
fopdoodle
forward curve blade
freely-movable bearing
funisitis
germanizing
goal celebration
half cross stitch
homofullerenes
interleukin-2receptor
irradiation container
isocyanato group
kui
laurel oil
layer ploughing
lorettes
melinophane
Mniodendron
modified nyquist path
moleski
Morris Ranch
mozzarelle
nondetergents
oblique aberration
Oijen
oil-seed camellias
Okahao
Ouantonou
performance curves of water-turbine pump
PETALICHTHYOMORPHA
phasings
pile up effect
plasticity matrix
pronucleuss
pyroelectric display
Rankine efficiency
regrexit
residual current compensator
resolution-enhancement
reverse efficiency
Romanomermis
shifting transfer
shrench
spin spin
split draft
staith
strength and elongation
superior goods
supernaturals
sus-s
tawny eagle
teach oneself
teacher burnout
text-killer
the princess of wales
transverse pitch of rivet
trend channel
valve lever bracket
verification and control
vigoursly
washed out soil
wind gaps