无甾醇原体属

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(132) / 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(136) / 评论(0) 分类 探索与发现2012年

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(156) / 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(153) / 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(138) / 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(134) / 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(152) / 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(140) / 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(127) / 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(167) / 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(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(144) / 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(166) / 评论(0) 分类 探索与发现2012年

This is in Africa rarely seen, a lush water world. Some creatures are completely at home here. These are lechwe, antelope with hooves that splay widely enabling them to move at speed through the water. For others, the change is far less welcome. Babo

发表于:2019-01-23 / 阅读(113) / 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(138) / 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(146) / 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(157) / 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(130) / 评论(0) 分类 探索与发现2012年

BEIJING, Dec. 11 (Xinhua) -- China is faced with severe challenges in collecting enough blood plasma to produce medicines, Health Minister Chen Zhu said Sunday. Chen called on the public to join blood donation after donating blood plasma at the Beiji

发表于:2019-02-07 / 阅读(151) / 评论(0) 分类 英语新闻

CHENGDU, May 5 (Xinhua) -- Chinese Health Minister Chen Zhu donated plasma on Saturday in Chengdu, capital of southwest China's Sichuan Province, and called on health workers to take the lead in blood donation to ease the country's blood supply short

发表于:2019-02-18 / 阅读(151) / 评论(0) 分类 英语新闻
学英语单词
acting consul
bacterial plaque
Ban Taling Sung
barology
beefwoods
beet chips
blennometrorrhea
book profit
bridge diagram
by product method
castanopsis cuspidata schott.
chamber of commerce noting fee
cold starting ability
curing group
deformed joints
Desethylamiodarone
Desire of all nations
digital tuning indicator
disaggrega-tire
disputable
docking telegraph
double readout
economics of commerce
edge-frame
exothermic change
fecundation
Ferké
fixed-point temperature
Gespunsart
golf equipment
gownmaker
happy release
hardware cursor
hardware probe
hierarchical relationship
Homoaromoline
hoshinoes
implication of law
infranchising
infratemporalis
Inglefield Bredning
ingredients of concrete
integral regulation
interlaced GIF
jute insulated cable
large hub screw propeller
latscher
long and short armed frame
lookout towers
Mallorcan
mandellas
mantle leaf
Masalaka-besar, Pulau
neptunoyl
nerve ring
North Pacific Ocean
Nothapodytes foetida
once-famous
open fracture
optimal policy curve
oxypressin
Paraixeris serotina
pars intramuralis
periocular
physiological disturbance
physiology of seed
PIC method
plentifulest
point line
polygalic acid
popfictions
population continuous growth model with time lag
press marked pottery
program uncertainty
pulsating current traction motor
quarter belt
radar sounding
reedlike
revascularizing
romeites
roseberry
Ruya
sedinon
sensltive
service interruption
set sill
Shelvey
shroud leakage
stabilized prints
stuffbak
super-Poisson light
taeniolabidids
telecare
the little ice age
timber-company
trisonant
trugreen
tumor in vertebral canal
warhammers
water mustard
waverlys
welding bead length