4-苯乙烯吡啶,γ-苯乙烯吡啶

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(118) / 评论(0) 分类 探索与发现2012年

SARAH MCCAMMON, HOST: The indie rock band Pedro the Lion is known for its sometimes dreary lyrics that take on internal conflict often filled with religious angst. (SOUNDBITE OF SONG, THE FLEECING) PEDRO THE LION: (Singing) Who shall I blame for this

发表于:2018-12-17 / 阅读(122) / 评论(0) 分类 2018年NPR美国国家公共电台2月

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(120) / 评论(0) 分类 探索与发现2012年

Hey 嘿 Beautiful, beautiful, beautiful, beautiful angel 美丽动人优雅纯洁的天使 Love your imperfections, every angle 连你每个不完美的角度都喜欢 Tomorrow comes and goes before you know 时光飞逝你不曾知晓 So I just had

发表于:2019-01-03 / 阅读(130) / 评论(0) 分类 听歌学英语

Grafting is a way to produce plants from pieces of existing plants instead of seeds. Branches or buds are cut from one plant and placed on a related kind of plant. The branch or bud that is grafted is called the scion. The plant that accepts the graf

发表于:2019-01-12 / 阅读(151) / 评论(0) 分类 2010年VOA慢速英语(五)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(140) / 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(137) / 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(122) / 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(122) / 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(136) / 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(121) / 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(107) / 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(148) / 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(115) / 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(131) / 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

By Nico Colombant Bokoni 08 February 2008 While former Liberian president, Charles Taylor, is being tried in The Hague for alleged war crimes in Sierra Leone, his imprint is still being felt in the neighboring country of Guinea as well. Some of his f

发表于:2019-02-05 / 阅读(96) / 评论(0) 分类 VOA常速英语2008年(二月)

China says a multi-billion dollar oil deal with Iraq is still being negotiated. This contradicts reports last week from Iraqi officials, who said the deal had been signed. Daniel Schearf reports from Beijing. China's Foreign Ministry on Thursday sai

发表于:2019-02-11 / 阅读(118) / 评论(0) 分类 VOA标准英语2008年(九月)

Lesson 231 You owe me one! 1.You owe me one!你欠我一个人情! 2.I stil lowe for the car.我还没付清 这辆车的钱。 3.I owe ou an apology.我该向你道歉。 4.I owe my parents a lot.我十分感激 父母。 5.I owe you five dollars.我

发表于:2019-02-12 / 阅读(117) / 评论(0) 分类 辛沛沛NO-BOOK 辛沛沛傻瓜机口语极短句
学英语单词
abiogenesists
absolute deviation
ACAU
aerobryidium filamentosum
air evaporation valve
Alertol
aluminum citrate
amor patriae
antiroyalty
Ariano Irpino
Ausonius, Decimus Magnus
balkening
bartholinitis
be happy for
benzacridine
bump protection flight control system
carrotless
cholagogic purgative
cold position
compensating-pressure transducer
conductometric-titration
crab fishery
creeping chill
critling
dacryocele
damaging goods
dermatitis rhus
disoriented attachment
dollar forward
dual tandem shaker
dump him
elevator test bed
Emoc
epaulettes
exchanger heat
extra-base hit
extra-formal
figured veneer
foil-borne condition
forge works
freeing for adoption
gear box of wind turbine generator set
gender stereotype threat
germanium photosensitive resistance
Goodyera repens
ground robin
gyrosynchrotron radiation
high-wire
hold ... dear
HPLA
humanitian
hypoergy
inductive filter
invitiate
isopentaquine
ITWF
kolinization
kraag
Lago Posadas
larix deciduas
line admittance
lobulose
make a great deal of difference
makss
Manchurian candidates
microlera kanoi
microsurgical technique
more wit in his little finger than in your whole body
Myoscint
nationales
nicomelane
oca
oculodentoosseous
oxyphil cell
phosphomimetics
planing angular surface
plumose stigma
polarisation angle
program operator
puncheons
pyrosulphate
rami scrotales posteriores
rayney
redbed
Salto Grande
semi boiling
semisubmersible drilling rig
single addressed telex
sink into the grave
solitary tract
Sollas
spider belly
sratch race
star twisting
stem checker
taste-producing component
transistor noise characteristics
venae prepylorica
wear pattern
White Lias
without fear or favour
Wuyue Bandao