[网络] 环烯;环烯烃

发表于:2018-12-02 / 阅读(345) / 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(251) / 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(248) / 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(319) / 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(405) / 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(376) / 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(301) / 评论(0) 分类 VOA标准英语2010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(283) / 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(296) / 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(271) / 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(254) / 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(289) / 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(268) / 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(249) / 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(274) / 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(311) / 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(280) / 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(286) / 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(304) / 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(264) / 评论(0) 分类 探索与发现2012年
学英语单词
Alibo
anastatica hierochuntica l.
Anglo-Egyptian Condominium
As the old cock crows,the young one learns.
atrial standstill
aurigation
automobile carrier
axle generator control box
bactoagglutination
be well versed in
beggars' barms
Bellinzago Novarese
bore evacuator
cast steel valve
Catorce
cauvin
Center Cross
clausocalanus paululus
COMAFFOR
confine spaces
crater chain
cup-and-cone bearing
deficiency disease
dental ivory
diagonal test
dry cleaning shop
electioneerers
facial palsy
fractional-ownership
gamendazole
Gennadios II Scholarios
globidiosis
grinding pebbles
harazin
hereditary palmoplantar keratoderma
hyla cinerea
ideal mixing stage model
inclined face hemihedrism
indicator plankton
individual response stereotypy
inter company deposit market
knife blade cover
land increment
lose height
magnetically focused cascade image intensifier
makes water
micopylar membrane
molings
mopologist
multideck clarifier
multiple-conductor concentric cable
muscle car
napoleans
nebulosities
nelumbifolia
neoxylophaga lobata
numerical key
odograph course tracing table
packet transfer
Panunzite
Parkman, Francis
peeping tomism
Phantasos
pistol-shot
plus thread
Porcos, R.dos
procuror
pulmonary tubercle
pump case
quasiment
rami communicans fibularis
rayleigh wind-speed distribution
real-time information management
relative area of transvariation
Romajikai
rothbury
running hours indicator
salt pack
single beam molecular absorption spectrometer
sketching easel
Slaidburn
sodium barium niobate ceramics
soope
souther
speed-meter
spring-backed type indirect pilot
staddles
state acceptance testings
Suir, River
sulphaphenylpyrazole
surplus superelevation
T'aech'ǒn-gun
three-way latticed grid
tritoniss
true-boiling-point analysis
unauthorized practice
use a computer
Voltarol
wave-CISK
weakly mixing transformation
weasiness