胆钙化醇,维生素D3

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(183) / 评论(0) 分类 探索与发现2012年

The Chinese offshore oil corporation known as CNOOC has abandoned its bid for UNOCAL. This would have been the largest-ever purchase of an American company by a Chinese firm. CNOOC had put forth a bid that was higher than the competing bid from US o

发表于:2019-01-08 / 阅读(317) / 评论(0) 分类 2005年NPR美国国家公共电台

By Greg Flakus Houston 26 January 2006 This week thousands of movie directors, writers, actors and Hollywood executives are huddled together in the ski resort town of Park City, Utah attending two ind

发表于:2019-01-09 / 阅读(233) / 评论(0) 分类 2006年VOA标准英语(一月)

New York City is not only home to the nation's most diverse population, its public school system also has the largest variety of so-called specialized schools. These academies concentrate on everything from science and the performing arts to social

发表于:2019-01-13 / 阅读(211) / 评论(0) 分类 VOA标准英语2008年(六月)

The State Department said Friday U.S. officials are looking for a reciprocal gesture from Iran after President Barack Obama's conciliatory holiday message to the Iranian people and government Thursday. Mr. Obama said in a broadcast for the Iranian n

发表于:2019-01-13 / 阅读(220) / 评论(0) 分类 VOA标准英语2009年(三月)

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(209) / 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(188) / 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(179) / 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(205) / 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(190) / 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(170) / 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(203) / 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(215) / 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(193) / 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(199) / 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(211) / 评论(0) 分类 探索与发现2012年

On the eighth tee, Dannys cell phone rang just as Roy was getting ready to hit the ball. Roy hit another bad shot. He glared at Danny. Danny looked at him again. Im a doctor, Roy. Im on call for emergencies. What if your great granddaughter was in a

发表于:2019-01-27 / 阅读(217) / 评论(0) 分类 365个英语简短小故事

If he says one more thing to me, Im going to hit him, Roy thought. Roy was thinking about Danny, a fellow golfer he had just met today. Danny was a successful orthopedist, 60 years old and quite overweight. Roy was a retired Army officer, 80 and wiry

发表于:2019-01-27 / 阅读(248) / 评论(0) 分类 365个英语简短小故事

By Benjamin Sand Islamabad 06 March 2006 Maroufa, 4, receives polio vaccination in Kabul, Afghanistan, Sunday, March. 5, 2006 Afghan volunteers are vaccinating millions of children in a nationwide ant

发表于:2019-01-31 / 阅读(269) / 评论(0) 分类 2006年VOA标准英语(三月)

By Mike O'Sullivan Los Angeles 14 February 2006 Hollywood's motion picture academy honored nominees for the Oscars Monday, as the countdown gets under way for the annual film awards. A luncheon gave n

发表于:2019-02-03 / 阅读(287) / 评论(0) 分类 2006年VOA标准英语(二月)
学英语单词
abbreviating keyboard command
aculeate-serrate
alfine
all and all
allowable opening diameter
aluminum pipe
andelman
antiseptol
arbitrary-sequence
area lunata
bench excavation
bilingual education
camera study
caricature plant
carve ... up
chromis weberi
comb.
conveyance channel
dead weight piston gauge
defect solid solution
deflector keel
detuning capacitor
drawing room model
East Cranmore
electron deficient
emblematist
enterolacton
externally heating
f-c
Facies digitales plantares
family reunion dinner
fluoroses
gas coolant
gastric intussusception
geometric tracery window
ghet
Glyciphagus domesticus
golden maidenhairs
golden spikes
hapmap
hardware rendering
hemsleys
hoisting sling
hughes-hallett
I just died
in-housest
incident particle
incident type code
integral equation method
interior wire
knuckle tooth
Kraaipan
lending limit
mackarness
magnetometric
make one's acquaintance
master mold
method by inversion
Mexicanizes
mid-year review
multiple-lens photograph
mutawakil
naked domain
other recordable optical disc drives
outside shell
owl creek mts.
palmityl deacylase
Panama weave
pea stone
perspectively
physiological colorimetry
policy practitioner
pseudotriakid
ptak
purchase expense
qapla
r-j
recarry
reciprocal correlated colour temperature
retroverting
samourai
sardelle
scalene fascia
scawbard
Searles Lake
sedna festival dance (esquimaux of baffinland)
seyrigs
shell type
side-kicks
silver thread
soft scales
sounding balloon
stearoptene
synaeresis
system prompt
therebehind
thiopurines
toughen
trapped-stock bender
variant stress
viola acruata bl.
Waiau River